Delete Overlaps function for Midi played notes in play mode

Is there a function for this?

…also I’d like to know if is there a function for select all the midi events in piano roll…something like cmd+A

You can use Select More in Play mode: select one note in the piano roll, then type Shift-Command-A and you’ll see the selection grow.

There’s no command for removing overlaps in the current version, but that’s coming in the next update, which will be available quite soon.