For offering a AMA question, and answer style format; I guess it depends on how problematic that would be, i.e if they are low quality questions, and encourage low quality responses. However, if they aren't particularly problematic I can't see too many issues with that from my point of view.
However, offering incentives, particularly not in the games or rounds, and not in Bitcoin is usually a no go, so I'll leave the quote below of mprep;
Incentivizing posting in exchange for bitcoins is allowed but restricted to Games and Rounds. The incentive doesn't have to be guaranteed for each and every user (e.g. running a free BTC raffle with only 1 winner is completely fine). As such, I don't see anything wrong rules-wise with giving away free spins at a casino, provided that if you win during a free-spin, you get BTC.
The best solution to this if rewards are absolutely necessary would be doing the AMA in games, and rounds, and offering the rewards in Bitcoin.
In short; AMA sounds fine,
probably. Rewarding users for posting depends if the rewards are Bitcoin based or not, and if so its probably more appropriate to do the AMA in games, and rounds rather in the project thread.