should i?

If you have less than 150k GP, don't bother.

I sold it T-2 didnt work for me

I know what you mean. I picked it up once, and didn't like it already :L

i know its epic but im startin to get sick of it i feel i can do better with a p90tr se and xm8+ super elite + the exp passes that i dont have.

You might, for 30 days. Then you'll kick yourself in the ass for selling the T2. If you're sick of it, just buy a GP gun, and use that for a bit, then come back to the T2. It's really quite a good gun, but you can get sick of it.

Not if you have a lot of perms / you don't use that certain gun...

Until you want to use it again.. Only time I would suggest selling a perm would be if you can buy a GP perm that you feel you're better with. Never trade a perm for a lower duration.

also the account that im on got banned and then unbanned should i reinstall CA like it says?

Nexon told you to reinstall? When I got unbanned they didn't say anything like that to me.

No, just no. I have the T2 perm and it's fucking amazing. P90 TR is also amazing, but when it expires you'll have to buy it with NX or try the 5 Shot again, which wastes GP. Unless you have 200+ GP don't sell your T2.