One thing I notice in the new system is it seems no longer possible to "bump" donation cash out requests. Once you send a request the option disappears. At least I cannot find it.
nothing was changed in that regard, i think you might just be forgetting where the "cash out" link is (Profile -> DonationCredits -> Request Cashout).
If feature requests are appropriate I still think it would be cool to let posters delete their own posts, perhaps within some time limit, without Mod intervention.
Yes, or at least some way to automate the request for post deletion. The way it has to be done now is you would edit your post just making the content something like "Please delete this post".
The only reason the option was removed was to prevent some mass deletion of a person's posts during a fit of anger or someone guessing someone's password.