Originally Posted by new optimus
You can make a backup in twrp recovery, or cmw recovery.
That gives you a fully restorable stock rom as you have it right now.
yes it is safe to flash a tmo rom, though I am unsure what you mean by access to phone and data?
If you mean installed apps, no those will be formated over usually, though the playstore will still have record of them all so you could just redownload.
and all your contacts are stored with gmail when you sign back in they will be add back into the phone.
What I meant by "phone and data " was if by installing a tmo rom if I still have access to metropcs, I am used to install roms specific to carrier so this is bugging me.