i think there should be should be 2 modes. step seq and piano roll for all clips.
ableton would benifit a great deal with a step seq. a friend of mine has cubase 5. the pattern/step on that is top class. you can slice a loop, add the sounds to cubase 5 new drum maschine and then add a step seq to it. we created beats so easy. much easier than making beats on native instruments which ive just wasted £450 on.
i know there is one in max for live. but future ableton needs one.