The purpose of philosophy I confess I wonder just what questions philosophers have asked despite "enormous pressure" not to do so. Of those mentioned in the OP, the only one I think has, and may still, generate serious opposition or controversy is "What is God?" Some (like me) may think that question isn't or shouldn't be of any concern to philosophers, but outside of wishing it not be asked or discussed and perhaps sighing when it is in my presence, I can't recall enormous pressure being applied to prevent it from being asked.
Efforts made to prove that God does or does not exist seem to anger some and provoke bitter responses, it's true, but the unfortunate prevalence of such efforts establishes that any pressure to suppress them has been ineffective.
There is the example of Socrates of course, and whenever and wherever the Abrahamic religions or others similarly intolerant and exclusive hold sway there's very serious pressure applied to repress the question IF it raises other questions related to whether the God favored by the powerful really is God.
I think that the questions mentioned in the OP are so abstract that the claim there is "enormous pressure" not to ask them isn't credible. They lack context--like so much else in philosophy. Imagine enormous pressure being applied to prevent consideration of what it means to know something, or what it means to exist. So I ask for examples of these dangerous questions it's the purpose of philosophy to ask and address.