What Are the Chances We’ve Been Visited by Aliens?

Some move with such acceleration and speed that some form of mass or gravity control would be essential.

Not "or gravity", it's a definite "and". Some of those supposed accelerations would crush anything biological, and probably even some weaker metal/other. They'd have to have some kind of inertics system, though possibly unmanned drones would be an acceptable answer too.

It could be demonic forces, aliens, or our own secret tech. God created a vast universe and it is full of wonders. I think life is an intrinsic, inevitable phenomenon due to the design of our creator, that it arises everywhere where the conditions are right.

Exactly. If we assume the Christian Gods is the correct answer, then what's the point of creating billions or trillions of different worlds, if all of life in the universe is only placed on a single one of them? Sure, stars do something for us here (not much), but any worlds around those stars have zero practical effect on us.

So why should we assume that never happened before, in hundreds of millions of years? If that did happen though, why did they seem to bug out from the surface of the planet?

Those aliens are demonic spirits.

Perhaps, but we're not going to see a real-life version of the ending scene in Close Encounters of the Third Kind. Why? Just one look at humanity answers that question.

Sorry if I offended by my earlier response.

Here is a book review that discusses the MIT conference on alien abductions. Skeptics were given respectful opportunity to present their sides of this controversial topic.

MIT sponsored the first academic conference on alien abduction in 1992. Over five days, 54 professionals delivered 150 presentations (Source)
They covered “the many dimensions, layers and schools of thought of this controversial, difficult and confusing subject.” Michael D. Swords. (1997). Review of Alien Discussions: Proceedings of the Abduction Study Conference Held at MIT. Journal of Scientific Exploration.
BOOK REVIEW
Alien Discussions: Proceedings of the Abduction Study Conference Held at MIT, Cambridge, MA by Andrea Pritchard, David E. Pritchard, John E. Mack, Pam Kasey, and Claudia Yapp, editors. North Cambridge Press: Cambridge, MA (1994), 684pp., ISBN 0-96449 17-0-2.
This is a formidable book (almost 700 pages) about a controversial, difficult, and confusing subject. That line should indicate why it will not be well read by our academic colleagues. However, for anyone with the slightest serious interest in the topic, it should be. Persons wishing to immerse themselves in the many dimensions, layers, and schools of thought about alleged UFO abductions cannot find a more eclectic and stimulating pool.
An occasion to bring everything from well-conceived-academic quality research to partially baked intuitions onto the stage.
The book presents an essentially verbatim account of the talks, panels, and discussions of the Abductions Study Conference of June 13-17, 1992. The editing of these, especially the accurate transcriptions of audio tapes and attributions of comments, was a heroic task. The editors, particularly the indefatigable Andrea Pritchard, are to be saluted for producing a volume which (barring videotaping) comes as close as possible to placing the reader right there in the MIT lecture hall alongside the participants.
There are nearly 150 separate presentations transcribed in the volume. World famous UFO researchers like Budd Hopkins, David Jacobs, and John Mack hold forth beside relative novices and the abductees themselves. Representatives of some non-U.S. research also contributed (ex. Brazil, Canada, United Kingdom, Australia).
Even the skeptics were represented and spoke. Actually, it would be more accurate to have used the term “debunkers” (or absolutist a priori skeptics), since the conference had many true skeptics in attendance: the UFOlogists themselves, who disagree (amicably) with one another, and expressed those disagreements here.
This conference was deliberately eclectic. The field of study is new and in much internal debate. The program was meant to be an occasion to bring everything from well-conceived-academic quality research to partially baked intuitions onto the stage and roll the mix together to see what we could see. The contributions to the book are, therefore, of a wildly diverse quality. If the reader is an intolerant academic purist, much of this will not appeal. If the reader is a flexible explorer, it should be stimulating caveat emptor. There seems to be much gold in here somewhere, but which the gold and which the hematite?
The conference marked a UFOlogical watershed of sorts, as it is the formal moment symbolizing the cracking apart of the almost monolithic paradigm of UFO abductions which issued from the seminal work of Budd Hopkins in the early 1980s and had come to dominate public UFOlogical thinking. Hopkins’ work, strongly supported by the research of David Jacobs, pictured the Abductions Phenomenon as not only truly extraterrestrial in origin, but essentially uncaring and negative toward its abductee victims. Although some counter-views existed, they carried very little impact in the mainstream UFO literature and symposia of the later eighties and nineties. The European researchers had rebelled and created a non-extraterrestrial psychosocial hypothesis, and the communities were engaging in a trans-Atlantic debate wherein the Hopkins Jacobs school of thought was largely thought of as the sum of American Abductions Ideology.
The conference at MIT split the public unity of American researchers into (at least) two major schools of opinion, which deeply disagree to this day. Both continue to believe that the phenomenon is extraterrestrially-based. Hopkins, Jacobs, and others were present to elaborate what some have come to refer to as the Dark Marauders view of abductions. But conference co-organizer, and world-known Harvard psychologist, John Mack, presented an entirely different spin: these experiences are extraterrestrially caused but are positively transformational for the human spirit. Despite the severe disagreements that followed, this gave researchers like Joseph Nyman a foundation stone authority figure around whom to rally. The so-called pessimist and optimist schools took shape before the attendees’ eyes. A third major position, of course, exists within the U.S. research community, the “probably extraterrestrial but I don’t know the details” viewpoint. They were also there in the persons of Mark Rodeghier, Stuart Appelle, David Gotlib, et al. Kenneth Ring also presented his interesting view comparing abductions and near-death experiences, and David Hufford did likewise regarding the centuries old Old Hag phenomenon.
The issue of psychology must be firmly addressed before the subject can even get off the ground… And, the verdict is generally positive for the persons reporting abductions. The Proceedings are split, like the conference itself, into a stack of logically organized sections, as follows: Introduction; The Abduction Experience; Evidence; The Psychology of Abductees; Hypotheses; Ethics, Therapy, and Investigation; and What Should We Consider Next? Sections 2,3,6, and 7 feature some talks and panels by the abductees themselves, and are among the few places that a reader can get a relatively undistilled feeling for what these folks are all about. At the end of the volume, the Pritchards have tacked on a 50-page investigator survey analysis by Thomas Bullard. This analysis is done with Bullard’s usual awe-inspiring thoroughness, and with the insightfulness also displayed in his seven symposia contributions.
Being an empathetic but semi-stick-in-the-mud academic, this reviewer was most impressed with Section Four: The Psychology of Abductees. Because the major skeptical barrier to taking this phenomenon as anything other than the Carnival of the Human Mind is the assertion that the abductees are all liars and confabulators (at best) or psychiatric (at worst), this issue of psychology, must be firmly addressed before the subject can even get off the ground. This is a point which abduction researchers often agree to, and then naively assume that no further attention need be paid to it if one study or one authority pronounces abductees “OK.” Fortunately, the symposium did not short shrift this issue, and, led by the extremely important work of Rodeghier, Goodpaster, and Blatterbauer, give an intellectually honest and well-balanced assessment of what is known. And, the verdict is generally positive for the persons reporting abductions.
This continuing emphasis is all the more important due to the relative weakness of Section Three: Evidence. Despite all manner of anecdotal claims which (some at least) should in theory be testable, basically none of the physical attributes of the reports are documented (even today). The almighty power and control of the ETs can be alluded to explain this lack (and it is a sufficient hypothesis), but that is not very helpful in the long run for acceptance. If one is dependent upon testimony, one better continually demonstrate dependability.
Whereas that last analysis might not be welcome to those who have already concluded upon reality, reliability, and reasons, I do not apologize. The subject matter is astonishing, and perhaps astonishingly important, but to this reviewer is not in a state of fixed certainty. In fact, this is the charm and the value of this book. In these pages are all the puzzlements, complexities, and arguments of an exciting something, bursting to be revealed. This book has no conclusion. That’s why it is a good book. Let a free wind blow through the attic of your consciousness and read it.

If you cannot control your wildly irrational thoughts, you should at least try to hide them.

Could you please elaborate? Which “wildly irrational thoughts” are you referring to?

100%..! Angels (Cherubim) are aliens, are they not.??

'Visited' by aliens? If you mean 'ET's? Heck, no!

We (both US and PRC (Politically Repressive Canada)) are BEING INVADED BY ALIENS, ALL WELCOMED BY SOCIALIST 'LEADERS' all bent on 'burning it all down', so they can 'build back ~~better~~ ALIEN'!