While much of what he has released over the years has been unfortunately damaging to the US, it's never been proven to be incorrect, and is generally accepted as 100% genuine. My guess is that would be the case here once again, and this country desperately needs to know the truth, for a variety of reasons.
Respectfully, no. I’ve given immunity deals. The suspect must show the goods and have them verified, otherwise it will blow up in your face. Remember, giving him a deal means he’s selling his testimony. This does not generally play well before juries.
And, no - not everyone “desperately need to know the truth”. I would say most in power and the press feel just the opposite here if it vindicates Trump.