I Try to Write Good Notes of My Piano Compositions Using the Midi and Garageband and Came Across 3 Problems:

1) the low notes in the right hand key go straight to the left hand key (and the high notes in the left hand key go to the right hand key). how can i fix this? it doesn't go by dragging or adding notes.

2) sometimes instead of writing a half note, it writes two quarters connected with a bridge and it doesn't let me fix it.???

3) sometimes it writes breaks though in the "piano roll" there is not any. and it doesn't let me fix it.???

i would appreciate your help very much.