For me you've over-complicated the backup/restore stuff.
In Plesk 8.6 it just worked with little to no issues (certainly in comparison to later versions), Plesk 9 made it more complex and I still don't understand the conflicts questions, nor do I get consistent or reliable behaviour from the restore process, I can see what were you trying to do and I can see the benefits of it, but its now too confusing and inconsistent.
Every time you ask me to do a survey (Parallels I mean) I put on the survey that features are great and that I like the features that are being introduced into Plesk, but that it is much more important to me that things work and that they don't fail (well I always put fix bugs before introducing new features same thing, but you might go check my survey responses!).
I stand by that, and its relevant here, I think the majority of people on these forums are here because they have had issues, or they expect to have issues, and they would happily swap functionality for reliability. If I have to do each backup/restore in a certain way, rather than having flexibility then I'm happy with that so long as I know that I can rely on the backup/restore process.
We are (self made) lucky though, on physical servers we also run r1soft CDP so we can restore granularly through that and don't need Plesk server backups, we offer Plesk backup functionality for customers because we don't provide them with access to CDP and tell them that it is primarily a means of insuring against changes and application upgrades. On Virtuozzo we run CDP and the Virtuozzo backups both of which give us granular restore outside of Plesk itself.
Hope this helps,
Paul