1 through 4 are handled through vb4 plugins
Our application integrates against the user database of the forum and we load the vb
header footer style around our application.
You set permissions for usergroups in our admin panel and you can install it in its own database or the vb
You can run a test copy as long as it is not web accessible to everyone.
I cant really tell you anything about vb
mods as I do not have much to do with vbulletin.org or there works. Much like vb
we support our default code and not mods.