[BRX]

I think you're correct in thinking and priorizing the use of a tablet with stylus and finger.

My observations came from working with a mouse at a PC though. So far left and right click have the same action.
Maybe it's possible to assign the right click (or equivalents) for selection?

An all around better way IMO (if it is possible) would be that an existing stamp/annotation would be selected if it is clicked
and an insertion would only happen if it's in "free" "annotationless" space. So the selection tool is automatically applied if an 
existing notation ist clicked.

It would certainly accomodate my work flow since I often 
insert at first and fine tune location and size directly after that.

If annotations are intended or have to overlap it's always possible to insert them next to the target and select and drag afterward.