I am admittedly not a big fan of rules and deadlines, but I think the bounty rules have too many clauses and constraints.

Motivating story: I recently set bounty on a question which had an incomplete but still interesting answer. I only started the bounty to make sure that there was no better answer to the question, which seemed to me a legitimate use of bounties at the time. When no other answers came, I let the clock run out, expecting that the only existing answer would be rewarded. When the answer didn't get the bounty, I read the rules again and finally saw the "created after the bounty started" clause that spoiled my plan. I could have read the fine print earlier and accepted the answer in the last few minutes, but that is a bit too much planning for me.