If my answer is accepted, but the give bounty button is not pressed, when the bounty period expires, do I receive the full bounty?
While bounty wasn't tied to the accepted answer in the past, now as per Jeff's answer it will be awarded if the answer was accepted during the bounty period. Note that this was never added into the FAQ, so it's double-secret.
The implementation has changed a bit to better accommodate careless bounty owners. :)
... then we assume the question owner liked your answer when they accepted it, and it gets the full amount of the bounty at time of bounty expiration.