As I have been reading some classics in the field of nuts and bolts UFO investigations, as other have, I began to see that there is a core of common elements that emerge.  The following is a list of questions and speculations that I would love to dig into more.

1. Most of the idea below would apply regardless of the visitors being based in space, ocean or underground or even some combination.
2. Some UFO sightings indicate that stuff on the ground is attracted up under the UFOs.  Some think this is the key to their travel and physics.  May create micro black holes with particle accelerators, thus circular crafts.  If so would emit Hawking Radiation to prove.
3. Why would many types of other space people come to earth throughout our history but now not interact with our civilizations?
4. Perhaps they did once interact openly and then it all went horribly wrong – ie the Noah flood and Nephilem.  The rebels could have become sensory addicts and gone rogue.    They were not necessarily trying to cause trouble, but the law of unintended consequences took hold. Their offspring could have combined the worst traits of both and deliberately set themselves up as gods to be worshiped.  The usual results could be expected.
5. Are we regarded as animals? Does an amoeba believe in elephants or a blood cell believe in a human?
6. Would you teach a monkey to launch a nuclear weapon?
7. Assume most craft seen around earth are robotic or remote probes.  There must be larger ships nearby ‘relatively speaking’ that maintain and deliver the probes.  There is no reason for alien people to have visited earth in person, as per our exploration of Mars.
8. If they are a fully space faring race, they may pass through our neighborhood regularly rather than travel directly between our world and theirs.
9. If they have very long lives (prolong or natural) then interstellar travel not such a big deal
10. Why come to our solar system?  Water as best stable form of hydrogen to resupply?  Do they need organics for their provisions?  Are they already mining our asteroid belts?
11. Did the modern atomic/space age attract a lot of attention from other space civilizations?  Seems correlated to timing and location of many substantiated sightings.
12. Use of robotic exploration of us negates the issue of time and distance from their home worlds.
13. Many UFOs have some kind of cloaking or visibility to a different spectrum, as per ultraviolet and inferred camera footage.  This explains the sudden ‘disappearance’ of UFOs being viewed.
14. UFO abductions are completely unnecessary to the overall picture.
15. Some UFOs seem to give off gamma rays.
16. Outer surface of some disks seem to rotate.
17. Why do government agencies not want to investigate?  Maybe it is a simple problem of classification.  No one knows what it is therefore, it is not in anyone’s job description.
18. Could our sightings be ghosts of future craft that ripple the space/time in some of their propulsion or transition states?  Not all, as the small short range types might not have time warping engines
19. Why come in waves vs consistent?
20. FAA radar does not register stationary or extreme velocity, so it is clear why many craft are not tracked
21. Mid sized craft May hide in bodies of water or remote areas when around
22. In-system and Interstellar craft Dark side of the moon or orbit opposite our solar orbit
23. Consider cruise ship full of tourist analogy,
    1. maybe there are here on safari
    2. we may be the equivalent of a zoo tourist stop
    3. some who visit take bus tours (cylinder), helicopter (disk)
    4. Some go camping and visit the ground in remote areas
    5. Some are wardens/rangers monitoring the impact of the visitors on the natives
    6. Different companies or cultures could be visiting with different purposes or types of tours
    7. I hate to say it but there could be poachers or exploitative rogues, in addition to well meaning visitors
24. Humans as slave race – engineered or otherwise
    1. problem – we make awful slaves, see history
    2. if they could engineer a race, they would strip out our wild unpredictable traits, basic husbandry
    3. We could have been collected to be slaves elsewhere, who are then dumbed down and modified for compliance
    4. But if they are as advanced as they seem to be then robotic workers and automation would be better than us
    5. Pleasure slaves? Galactic whore house?  Humans will breed with anything, but everyone else has standards.  Ick but plausible.
    6. Incubators for experimental bio-ware?
25. Are they colonizing Earth gradually?
    1. Why bother, just kill us all and take over.
26. Are they hybridizing with us?  Why bother?
    1. Consider the descriptions of them as gray with tiny nose, ear, mouth parts, mental communication and no ornamentation or individualization.  Note de-emphasis on any sensory enhancements to their environment.
    2. Perhaps they are borrowing us by transferring their “selves” into us in order to gain our rich sensory experiences.  Or more simply they may have lost that richness long ago and are now trying to breed it back in.  What if their culture totally lacks art, music, texture, etc.  Perhaps they traded self expression and sensory stimulation for safety and peace.  Great story arch.  Note similarity to demon possession.
27. Drugs – need I say more
    1. Intoxicated by lactic acid thus cattle mutilations?  Fun thought, reminds me of the old Visitor TV series.
28. Were we already related to them?
    1. Consider the fork in the road – multiple worlds are seeded and then eventually checked on
    2. Maybe they are from our sister worlds
    3. Based on our own mythologies the original master race could have planted us and others, then later the parental types may have been over thrown by our sibs.  Similar to a number of origin tales.  Some sibs are helpful, some exploitative, we are incidental to their power struggles.
29. I would like to think we are the most innovative culture.  Could they be seeding us with tech then stirring the pot to get new ideas out?  If their culture has stagnated then maybe the need some way to gain fresh experimental input.
30. Consider that US was contacted as assumed world gov leader after WWII and offered a deal for materials tech for silence or cooperation  More likely, not government but key defense contractors are hoarding the goods.  Ike and Gen. MacArthur warnings about the future.
31. Alien Races – Not necessarily from space, could be time or dimension
    1. Multiple races over time, wars documented in history Bahaga Vita and medieval painting
    2. Some are either shape snifters as per Native American folktales and many other encounter types or are illusionists who appear in aspect as expected by viewers
    3. Since manipulating human perception is infinitely easier than changing physical body shape, I suspect they are illusionists
    4. Are grays the true form or just the modern expected form?
    5. Assume grays are true form then:
       1. large eyes indicated dark adapted vision, maybe planet of origin not as close to star or longer days or winters, perhaps even inferred vs our spectrum
       2. small ears, mouth and nose suggest limited sensory input and expressiveness
       3. no body hair to retain germs and shed in small climate controlled environments
       4. communication by telepathic abilities would negate need of facial and body expressiveness, limited hearing in our range?  whistling and other odd noises in sightings
       5. grays could be a form of worker or drone, undifferentiated in gender
       6. may have not developed sexual reproduction, may only spawn by some type of self cloning.  particularly useful for long space voyages, since small isolated breeding populations would not present a problem
       7. lack of sexual reproduction may reduce some of the competitive drive between individuals, this is also consistent with their lack of individual ornamentation
       8. this might explain the focus on our reproductive methods in abductions as if studying a curious animal species
       9. the lack of individuation also suggests a highly homogeneous culture, if they are facing some kind of major threat or challenge to survival they are ill equipped to address, perhaps they are researching us for inspirations
       10. confined spaces do not seem to be a problem for them or crowding, so that suggests a very docile or cooperative society, again critical to space travel or confined living
       11. the apparent frailty of the grey bodies tends to indicated they are very far removed from any hunting or sport background, probably entirely vegetarian, low grav home world
       12. low grav home would have facilitated early development of grav reduction tech
       13. or conversely, their current form is an adaptation to space environments of low grav
       14. they are suspiciously well suited to long term space travel, so are they really organically engineered drones for that purpose and not representative of the races of their home world? have they rebelled against their creator?  are they trying to recover a lost skill with engineering organisms and experimenting on us?
       15. Why would they seem to function in our gravity with their spindly appearance and breath our atmosphere without assistance.  Seems like they would be crushed by our gravity after being in space so long, perhaps generations.
    6. Possible that most tales of supernatural beings are tied in to various ET types.
    7. Why would there be dramatic and open participation in human culture which then stops a few thousand years ago and degrades into various dark ages of collapsed civilizations?  Factions, interlopers?

Galactic Neighborhood

1. Any advanced alien race aware of our presence would, probably follow the same basic pattern we would when dealing with a frontier.  All of our cultural traditions agree that they have already been here.  The real question is which stage are we at?
   1. First send probes and scouts.
   2. Explorers and privateers might come next.
   3. Then scientists and missionaries.
   4. Then conquest and domination.
   5. Then revolution and diplomacy.
   6. Finally cultural assimilation.
2. There is no reason to assume that any craft we encounter here is driven by a live being.  If we can have Google car on the road, we can assume they have autonomous drones.
3. Space travel would not be a huge barrier to robotic, AI or disposable cloned pawns.
4. A species with a very long lifespan would not consider space travel to be prohibitive.
5. Why would we assume that a billion year old civilization would value a planet at all?  Even our own fiction assumes that one day we will live our entire lives in artificial colonies.
6. If an far advanced civilization wanted to genetically modify us, they would release tailored viruses not abduct individuals.  Therefore, abduction must have another purpose; pleasure, sport, academics, training.
7. One way colony/explorer star-travelers, who could sail at close to the speed of light would not be deterred by the time gap to their home world, since they would not be returning home.  Think in terms of galactic gypsies.