I think that it would much easier for KeePassX users to have a separate modal window for when user want's to edit an entry, because that way he can still see the list of entries (what's more, the edited entry would be highlighted in that list). Original KeePass do it in this way and it's much easier (at least for me ).
Look at it:
I'm impressed of what you guys are doing here and I want to get involved too. So, implementing this thing could be first thing I do in this project.
What do you think guys about that?