Can I use my Tmobile phone with a tmobile go phone sim card?

I have a T-mobile rzr and I was wondering if I go buy a T-mobile go phone and put the sim card in my old rzr will it work?

Yes it will.

yes it will work

Yes, provide both Tmobile is of same country. If not, you need to unlock. To unlock, I suggest you can approach Unlocking4u.com and specify the country,locked network of T-mobile Razr.Based on the availability you can get the permanent unlock service along with free instructions.