So you want it to be possible for bounties to be immediate. And, if these are abused to prevent quick closure, to have systems around that. Sounds to me as a way to make things more complicated than necessary.
The 2-day delay isn't only there to give a community time to close a question. It is also there to prevent the front page from becoming a rush to award the highest bounty.
I don't see a need to award bounties immediately. It's better to encourage users to polish their question first. Or edit it with the things they find after posting. That will also bump the question, and in a way that (hopefully) makes it easier to answer. And makes the question easier to find for the next user with the same problem.
On the busy sites like Stack Overflow or Ask Ubuntu, I could imagine shortening the time for a bounty - for example, 24 hours instead of 48. But in general, I see no need for the ability to bounty a question right after posting.
If a community decides that a question is out of the scope of their site, but should remain open anyway - we have per-site metas where they can rule on that. This should be extremely rare however - we got where we are by being strict about site scope. Off-topic questions that still convey value can be migrated or put under a historical lock, depending on the precise situation.