It would be better if you were to post your PC specs. that's including any other that might impede performance.
Getting stuck when aiming is known as well but I'm not sure Treyarch does care or are aware.
Check different graphics settings. Try this link BO2 Optimizations Summary - Steam Users' Forums
to see if it helps. Does not work with everyone.
Example: Try capping your frame rate. Low on everything...etc.