So in Kleopatra we moved away from Wizards for some time now. Still have them a bit but then reduced. Since the setup basically asks two questions:
a) Where should the folder tree live
b) To which certificates it should be encrypted

I think that this can be either reduced to a single page or skipped altogether. No one needs welcome or finish pages ;). Where we at the top you select the dir and below that the key. For the key I would suggest linking in libkleo and use the certificatecombobox. We probably need that, anyway if we want to support group keys.
If there is only one secret, valid key available I would skip that page altogether and just use that key. That should be the most common case.

The problem with adding libkleo widgets is that is that this then involves the keycache of Kleopatra which will also list S/MIME certificates and that can take a while.

Regarding the folder. I would suggest to just use the homedir/password-store on windows and homedir/.password-store on linux. On windows we should drop the . in the beginning as it just looks weird to the unknown user and to users that understand Linux it looks like "they wanted to create a hidden folder but did not do it". I guess .password-store is chosen for compatibility with qtpass default? Otherwise I would make it more verbose like "gnupg-password-store" to make it more clear that this belongs to the "GnuPG Password Manager".

For adding a folder I would use the standard Qt Folder selection dialog (which is the windows folder select dialog on windows), this allows you to create a new folder. And this will make it clear where it lives in the filesystem. It does not make much sense to me to have subfolders below your personal homedir password-store. To me it makes most sense to have a personal store that is encrypted only to your key in your Homedir and then some other folders encrypted for others, too in other dirs.

When I think of different folders I think more of different access groups for the folders and then it makes sense to use some shared filesystem location for them. This would also make it easy for users to add a common, existing folder. Also the new folder dialog says "New File" in the title.

For me on Windows adding a password did not work, works fine on linux I need to check the debug output why though.

This was just some first impression test.