Little newbie help on flashing a stock P4000?

[WhiskeyTangoFoxtrot]

I've got a stock P4000 updated with Telus' latest release of WM 6.1. I don't have any real complaints about the ROM, but like many other Titan users I'm a little pissed that a PPC phone like the Titan is such a letdown when it comes to Bluetooth - my Motorola S9 stereo headset just won't make calls with it. So I'm considering flashing a custom ROM to it because I've read they can improve your Bluetooth situation. I've read the FAQs, and I'm comfortable with the procedure, but before I start I've got a couple of questions for the group, if someone wants to field them.

First, am I likely to see increased (or functional, since it's not really functional now) Bluetooth performance?

Second, is there anything different about flashing a Telus phone over, say, Sprint? I know the hardware is all but identical, but are there any little Telus surprises in store for me?

Thanks, gang!