Some pieces of wood just harmonize with whatever blend it melds better with. After a while we forget what the briar adds to the aroma and flavor, but if you switch up with a meerschaum or even with cigars for a while and come back to the pipe, you'll start to pick up on the briar flavors. By green, I do mean unseasoned, like it still has some sap in it. I hate that taste most.
As far as draft and bowl shape, sure you can alter it, but is that "better?" I do this occasionally, but you have to be careful. You can smoke a pipe too hot by doing this also. And, who is to say that makes it better? Maybe for another pipe smoker that tight draft is just perfect. Or, maybe the pipe just wants that tighter draft, so you have to alter your cadence to comply. Only the individual can decide that. Besides, opening the draft on the stummel is easy. But, the flow is still constricted by the last little bit of the stem. You're not really going to be able to easily open this up without a little practice ...and a bent pipe, forget it.
But, I like the idea of playing with the pipe design. You can learn a lot about pipes this way. I encourage it, but you'll want to be good at using the appropriate tools. Anyways, my $0.02.