Some questions regarding recently acquired 8830 WE

Hello there, I've gotten my hands on a BB 8830 WE (on Verizon). It is originally from my father's company, and the phone line it was originally on has since been upgraded to a new BB Curve. I have some questions regarding this phone relating to how I plan on using it:

1) The phone is showing it still has 1x service; is that normal even though the line it was on has a new phone now?

2) The company's IT folks called Verizon on my behalf and provided me the unlock code for the SIM card slot. AIUI I can now pop in a 2G sim card from Europe (I will be in England) and use it there. Will I be able to use data services as well? Vodafone and O2 both have blackberry plans I can select from while I am there.

3) Can I wipe this phone to a factory state to remove any information that was on there, as well as any BES settings that may have been set up while the phone was still active with the corporation? From what I've read the unlock for the SIM is permanent, so if I can reset the phone I should be safe with that, right?

4) Currently the BB is running OS 4.2. Is it worth upgrading to 4.5, or even beyond to one of those hybrid OS's?

That should be all the questions I have for now; if you need more information let me know. Thank you!