@rankkorr To answer wether you can stay in demon form for extended periods of time, yes. It is in a near perfect situation though. On live, I was farming large groups of mobs with fast respawns so i was constantly attacking. With chaos wave on so many mobs and my wrathguard using its specials, I never ran out of demonic fury. I doubt there is any way to stay in full demon form in raids/dungeons unless in massive aoe groups.
Now that's what I called warlock pets :D