My experience with WB 10 on Windows 7; I used WB 10 on Windows 7 for a couple of weeks.
My main problem was that Pale Moon browser froze. This doesn't happen with WB 7 so I had to downgrade.
Other than that there was a little bug with window button tooltips not showing.
So I'd say that WB 10 works on Windows 7, just didn't like Pale Moon.
Usually it takes a reboot for the WB icon to show up.
Clearly WB 10 is where the development happen so I'll switch to that when I need to and hope Pale Moon is compatible then.
Right now I'm only using textures on default MS skin, so there are no skinning problems whatsoever with WB 7.
If skins aren't applied at all you should contact support. I assume you uninstalled WB 7 and rebooted before installing WB 10?