I think most people are reticent to critic him much, as he comes off as genuine to some people. However, his claims and the way he is presented can be looked at. Your summery:
Yes, Grusch had Top Secret (TS) clearance. Lot's of people do. It's not like getting a driver's license, but literally thousands if not tens of thousands of people obtain this clearance. My understanding, according to others here on the forum that operate in this area, is that TS clearance can be very compartmentalized and restricted to a "need to know" basis. Some have suggested that a person with a higher level of clearance my know less or nothing about a particular program than a lower-level person, because the higher-level person has no "need to know" about that program.
Grusch was primarily in a satellite recon program, he looked at satellite intelligence.
Due to the flap around the 2017 NYT UFO story, congress mandated an Unidentified Aireal Phenomenon Task Force (UAPTF) to look into UFO/UAPs in relation to the military. In 2020 the UAPTF was headed up by another intel guy, Jay Stratton who had connections to bizarre happenings at SKR. Stratton hired TV UFOlogist Travis Taylor as "chief scientist". The UAPTF was to find instances of UAP activity and try to explain them if possible.
I'm still unclear exactly how Grusch got involved as the story is somewhat vague, but it appears he was either asked to join the UAPTF or became the liaison from the satellite intelligence program to the UAPTF. In any event, his claim is that Stratton tasked him with identifying classified Special Access Programs (SAP) that might be related to the UAPTF.
His claim is that he found classified programs he was NOT allowed to be read into. But various people told him these programs were about crashed UFOs, reverse engineering, and that alien bodies had been collected. But again, he was not allowed access to these programs.
His claims are consistent with a number of UFO stories that have circulated for decades from a number of people. We even started a list of people that have made similar claims or could maybe be some of the people telling Grusch these stories.
See this thread (it's only a page or 2):
https://www.metabunk.org/threads/ma...ms-who-has-already-made-similar-claims.13110/
Some colleagues have vouched for him as a person. They can't really vouch for his stories, because they're all highly classified, right?
Without getting into the Machiavellian machinations of the current Republican slim majority in the House of Representatives, Congressman Burchett, under the influence of UFOlofists George Knapp and Jeremy Corbel managed to hold some hearings where Grusch repeated his same set of stories. There was some funding for AARO, the follow up to the UAPTF, but that was before Grusch. I don't know how much the White House is involved, if at all.
It's a bit more nuanced than that. Grusch may be retelling stories he believes to be true. Doesn't mean they are.
To date, after decades of these stories circulating, there is still little to no evidence for them.