In fact Zoom with a pen (with clicable button as mouse right clic emulate) is not truely a problem :)
As a pen graphic don't need realy touch the tablett
You rotate your object in the space (clicable pen button pressed) flying your pen over the tablet
on go on the Zoom Icon (screen bottom) disable the pen clic button and you can zoom easily :)

More confortable than a mouse :)

Ps the loops were made because I have taken the option
Draw Curve / Free Form/ Sketch and not "Throught Points"
So "loopings" can be easy created without my control due the micro pen movments :)