I doubt that the average CIA, FBI, and NSA worker is a democrat so I'm less skeptical then I would be if they released a report on say Edward Snowden.
The report and its unredacted sources will be subject to Congressional oversight from a Republican dominated congress. So far they have been supportive of its contents.
No. But this is an Ad Hominem fallacy.
When dudes be like "just trust us", and they've lied before, and they have obvious interests in lying again, no it ain't everybody's favorite fallacy.