Noob with questions

[wwz7777]

Hello to all,
I'm new to this world of ROM's, RUU, etc. I've hacked my Moto Razr V3M, so I understand the concepts. So, I have a few questions if someone could help or point me in the right direction. BTW, I have an XV6900 on Verizon.

1. Any post/sticky that explains what all the terms used are?

2. What is WM6.1? I'm assuming the next release/update to WinMobile6.0?

3. What is Rev A and some of the other features in some of the custom ROMs?

4. When upgrading the radio and then flashing a ROM to get GPS, is that satellite signal or the cell tower version?

5. Why upgrade/flash a new ROM in the first place?

Lastly, I had two HTC techs tell me that all versions of the Vogue have wifi built in, but that the carriers don't activate it in their ROM. True?

Thank you all for your patience and if the answer to number 1 will cover the rest, please let me know and I'll gladly do the foot-work.

This is an awesome site and you all ROCK!=D>