What to do with my x10?

[demongrowl]

I bought my x10a off someone in nova scotia about a year ago, and have been using it stock since then. I had to get it unlocked through one of those online services since the guy before me used up all the pin unlock attempts and didn't tell me. I have t-mobile. I use Helix launcher. Works like a dream.

but now i want to upgrade to 2.1. and I have a few questions. I don't see anything on my phone from the carrier, which I was told was Rogers. Does this mean my phone was already debranded?

This is what it says about the phone. Model: x10a FW version 1.6 Baseband version 1.1.27 Kernel version 2.6.29-rel semc-android@SEMC #2 Build # R2BA023

Do you need to debrand your phone to upgrade to the generic america 2.1?

Will this cause the phone to be network locked again?

Will upgrading to 2.1 cause the phone to be network locked again?

will any of this cause my data on the phone to get wiped? I have be using the sony backup, but i know this doesn't take care of everything, like apps.

Should i upgrade to a custom rom? will i still have timescape, mediascape, the sony contact book and sony dialer if i do?(i really like the look of the dialer and address book.)

I appreciate any help!!