Well, it turns out that Sprint was faster than I might have expected. I ordered the phone on Thursday at about 5PM, it arrived on Friday at about 2PM. Pretty good service!
Now that I've had it for a few days, I thought it would be helpful if I'd post the answers to my questions above for the next person who came along. So....
1) iGuidance (v4.0) works fine on the TP2. Better, in fact, than it did on the Mogul.
2) I never actually even installed GPSGate, as iGuidance doesn't seem to need it on the TP2.
3) PDANet (v1.
seems to work fine. In fact, this note is being posted over a PDANet connection.
4) PocketControllerPro (v6.01) works perfectly. Very useful, in fact.
5) MusicID doesn't work at all. But the Samsung Midomi product seems to serve the same need, and it works well (as long as you don't try to exercise its Menu, which causes it to crash).
And the TP2 syncs readily with my Motorola stereo bluetooth headset.
I started a new thread earlier today ("New Owner Questions") about some questions that I still have about the TP2. So far, no one has replied to it. I hope someone will be able to help me with my remaining concerns in the other thread.