Add an 'Undo ALL' and a 'De-select' option. Also the display should show a timeline in Min/secs, since that is what you need to know to Use the 'SELECT' tool. Also the speed of preview needs to be reduced.

I don't know how many levels of UNDO there are, but if you want to start afresh, it seems you currently need to reload the file. Time in Min/secs not SMPL is needed to use the "Select I" function. I selected a 0:2:50 loop and it took quite a noticeable amount of time before the preview was available. This would be very frustrating/un-useable if multiple edits were being performed.