Replying to 05 K2 P.E. Biding Position

Just recently purchased the Public Enemy and the store installed the bindings for me and they've mounted them on the midsole. I don't think I'm going to be doing alot of backcountry since I am in East Coast and probably be doing more park. I've read couple
people putting it +3 and +4. Would it be better to move it up somewhere near +3 and +4??? What would be the best binding position??? Also we'll it hurt the performance of the ski alot if they were to redrill another set of holes for the new binding position??? Also the guy at the shop told me that if I was to move the binding up towards center of the core I will lose speed in power snow conditions and etc. Please let me know on what would be the best thing to do at this point. Thanks.