I ate an In-N-Out twice in the same day back in 2002, and absolutely agree that enlarging a pipe's chamber diameter is a very tricky thing to do well. Going about it wrong is a spectacularly efficient way to ruin a pipe, in fact.I stayed at a Holiday Inn Express once, opening the bowl diameter sounds like trouble.
The stem should probably be addressed before anything else.
Enlarging a stem's airway without squoinking it isn't as simple as it sounds in many cases either, though. Lots-O-gotchas await. But it should definitely be done before messing with the chamber size.