NOTE - I no longer use Bblean, so I don't know if this theme still works.
You can use Pokki to disable the metro and hotcorners, which removes a lot of conflicts Bblean has with Windows 8.
Firefox may have conflicts resulting in "flickering" just add this to the exclusion list on the Bblean menu so Firefox's window is not handled by Bblean:
xul.dll:MozillaHiddenWindowClass
xul.dll:MozillaWindowClass