It is okay to wait. My Wylie was cryptorchid, and his never descended. Make sure your surgeon is *very* adept at these types of surgeries - bc Wylie's was not done well. Both my boys weren't neutered until about 10 mths old (Marcel bc he was a tiny).
The problem you might have w/ waiting is more marking in the meantime, but that was something I was willing to put with - bc I wanted to wait.
As for teeth, keep trying - and also you could buy CET petite chews either at ebay or Amazon (I get mine at both those places), ProDen Plaque Off powder, bully sticks.