1. HardSPL is the bootloader that controls what ROMs can be loaded onto your phone. You'll want to spend time in the stickied threads in the Upgrades subforum for information on all that.
2. There are several tweaks for enabling Roam Only mode which helps a lot in some areas. But that said, until HTC releases a radio update, tweaks of that nature are limited on the Touch Pro right now. You can find information on many great tweaks in the links in my signature.
Sounds to me like you'll want to dig through some of the posts on the Upgrades subforum.
