If anyone was an alien, it would be Tesla.
Mike, I could answer all your questions, but the answers would be as speculative as your questions.

The conspiracy theory requires the aliens to intercede in ways that enough people witness to justify a coverup to keep it a secret but not so many people that a coverup becomes in possible. Depending on who is in charge at the time, I would expect the gov't to use the evidence to call for more funding, preparedness, etc, not a coverup.

You also have a good point that the aliens could have interceded when humans and human-like creatures appeared and started the current mass extinction event or when humans developed agriculture.

This is basic anomaly hunting. Rather than starting with a hypothesis, you just search for anything anomalous and work it into the broad claim you want to be true. You can take a frequency counter (a device that measures the frequency where the power spectral density of background noise is highest) into the Bermuda Triangle or a purported haunted house and see some weird anomalies where the peak is higher than usual, lower than usual, jumps around more than usual , stays steady more than usual, or anything else. You can find something anomalous. It's more fun in an old house at night or flying through the Bermuda Triangle on a day with odd lenticular clouds.

I truly think woo is fun. I love these videos like Taco Bell.

Maybe someone does NOT want it restricted, and, of course, clickbait comes in to play. However, are you saying then that all these government documents quoted were faked, made up or? If so, I will send you to the site where they have about a billion documents released through FOIA. Next question: Why would the government release them in the first place/ Granted, the government probably has no idea what billions of documents have been held, and probably when a request is filed and a judge says do it, maybe they just grab boxes, but you would think they would redact whatever they didn't want released. So now you get into a circular argument, government is hifi=ding it, but releases documents, but they release documents to help hide whatever it is they really have, so it is not edited or redacted because they want you to keep getting more documents made up to cover up whatever they do not want you to know. It becomes so convoluted, that may actually be their own real aims.

My father was in Alaska in the 50's as a radar tech on the DEW line. They had a report from the guard shack of an object hovering overhead, and then it zipped over a ridge. He went over there with another guy in a jeep, and the saw a small ship about 20 feet across, landed on the ground. They drove down to it, and as they came upon t, it shot up and zoomed away at incredible speed. He waited until he was 72 to tell me, because they had 2 guys come up from some Air Force department that interviewed them for several hours, then made them sign non disclosure agreements with really bad threats in it about jail and prison. There have been hundreds of people who, in their very old age, said the hell with it, and told their stories. You have to admit, they have nothing to lose, and also why would they make up stuff in their 70's and 80's.?

The former defense minister of Canada did indeed do just that, and no one seemed to care. I can post a link if you want to see it.

I don't know, but my point is either a whole lot of stuff is made up and convincingly so, or there must be some basis for it. I was on active duty when some of those things happened, and they did happen. We were on alert in the Pacific and actually went to battle stations on the one where the whole site went down. They stood down about an hour later.

Obergs debunking is on NASA space flights. He has been paid by NASA to debunk other claims in the past. Does he have a conflict of interest?
None of the witnesses were in space, how is his conclusions proof that these highly credible multiple witnesses often with radar collaborating their sightings is false. The head of project blue book the The FAA district director the seem pretty credible to me.. Why they were spotted around nuke facilities is speculation.
That people saw anomalies and that at the same time malfunctions occured is a matter of public record thanks to the FOIA.

I doubt anyone has any original footage of these events but yes, the music was hokey.

I am not beyond believing the government has been doing a coverup for many years, after all, honesty is NOT a government character trait.