cecil: Does anyone play them with a touchscreen? Yes. Should they Hell to the no but they shouldn't be played with keyboard either and people do so IMHO not much difference.
Not really, you still have some control with the keyboard, now, touchscreen? Your fingers block some of vision and the lack of buttons makes for some weird choices (i'm currently playing Wayward Souls and i have to swipe up or down for some special attacks).
Now, fighting games with a touchscreen? I can't even imagine...