You say it "had a SuperTrapp" -- as in previously, but not now; I'll assume the bike is back to stock configuration, along with jetting and needle setting. Best guess is the idle mixture is too rich, and/or the float level is incorrect.
The XR's have a pretty heavy flywheel, so they don't respond well to "whacking" open the throttle. By design, two-strokes are more responsive (I'm generalizing here, so don't flame me)
due to lower frictional losses and the simple fact that they fire on every revolution.
As for gear choices for hills, you need to learn how to feel what the bike is doing. You can't choose a gear because "everyone says use 2nd". If you need more speed, upshift! If it bogs, downshift! I rarely stay in one gear all the way up a hill.