I don't think that's something we really want to do. Granting bot permissions hides someone from RecentChanges by default, which you wouldn't want as a normal user (well you might, but I don't think communities would).
Indeed. Communities also want separate bot accounts so it's easy to tell what contributions are automated and so bots can be blocked without blocking their operators.
Well, with OAuth, it might be possible to mark actions as bot actions. It would also be possible to revoke just the OAuth key that allows the bot to operate, thus avoiding blocking the user.
- Ryan