Sometimes it appears above the notes and sometimes below. I would like to be able to select which of these I get.
Slur position is controlled by the stem direction of the first note in the sequence of slurred notes. The slur position will be the OPPOSITE of the stem direction of the first note. You can still change stem direction in the remaining note(s) in the slur if you need to.
Wouldn't it be nice if they could slope diagonally to follow the shape of the note sequence more closely?