Altiman93

ok..first thing.. i have a 93 Altima XE, and just baught headers, and just want to know if i can go catless??as far as i know i only have one sensor and thats on the manifold, but do i have another by the cat?so bassicly im asking if i can go catless. second thing, is im looking for a strut tower bar for my car, and every time i look for one ebay pops up with the cheap looking ones, are they worth it? and last thing, i have mechanical seatbelts. when i open the door, they should move, but they dont. ive looked at other forums but havent seen to find the awnser. what should i look for, because i know they work. i kno they work because one day i was tryin to fix them, and i was pulling down on the little latch thing, and when i opend the door i can feel the latch move just a tiny bit..so i guess they have power to them, but what can i do?? i would appreciate everybodys help on this one, because of right now im frustrated!. thanks alot
Eddie