Demon Hunter would actually work pretty well on a gamepad - they have a lot of directional attacks which work great with a gamepad setup. Anything where you just turn the direction you want to shoot, basically. The problem with gamepads + ARPGs is Targeted Attacks where you move a cursor and click where you want an AE to go off. I haven't played Diablo 3 since like, before they changed Inferno at all though (beat all of it except Diablo, just got bored and put it down), so it's been a while and I'm not sure what attacks DHs are reliant on now.
As for PS4 and PC playing together - it's certainly possible to do, but people rarely do it. You can play the PS3 and PC versions of Portal 2 together for example. I doubt Diablo 3 will do this, but the possibility *is* there albeit a very small possiblity.
As for PS4 and PC playing together - it's certainly possible to do, but people rarely do it. You can play the PS3 and PC versions of Portal 2 together for example. I doubt Diablo 3 will do this, but the possibility *is* there albeit a very small possiblity.