I can see that with this new Ubuntu Browser is an attempt for Canonical to finally get up to speed with Windows 8 Gnome Shell type system. Win8 apps act much the same way (without touch screen) with the mouse etc...(I have been experiementing with UEFI, Ubuntu and Windowz 8 etc )
I am sure there are some macro bindings with keyboard + mouse that I haven't discovered yet. I tried to find some extra info on this new phenomenon-app but it is very sparse.
ok.. I'm off topic too
btw .. you can have both FF and Ubuntu Browser running at the same time and there is no conflict at all... I thought that kind of peculiar.