General will changing rom reset my phone

I'm running on a rooted g1, so I can use apps that require root access.
but recently I've been thinking of using the hero rom.

however I have no data plan and would have to go through a few hoops to borrow a sim card to log into my gmail.

basically: if I changed my phones rom, will I lose the apps that I have and will I be locked out with that stupid gmail log in screen that you get the first time you use the phone?

I honestly wouldn't mind at all If I could log in via wifi, but the darned thing forced you to use a data plan to log in.

 

thanks, well does cyanogen allow me to active my phone via wifi?
This is the only issue keeping me on the plain android software. I undertand that the official roms aren't going to allow me to use wifi, bur surely cyanogen does, right?

 

well thanks for that info,
I may update to cyanogen in the future in that case.

@nomad83: I tried that method before, I couldn't figure out the adb part.
as far as I can tell, google got rid of the older adb download (the one you need for that method)