What does it take to damage your cpu when installing?

They can bend and break, check if you see any bent pins.

Can't risk it to take it out again. Might as well just leak test it first, run it, and if something is wrong there is nothing to do anyway.

I had something similar happen to me once. I actually took off the cooling block and the cpu but when I was cleaning the block it fell and landed on the motherboard taking out about four pins on my lga775 board. To my amazement I actually tryed to realingne the bad pins and they all broke off. I installed the the cpu back in the socket turned on the computer and it worked. I actually ran it like that for about 4 years without any problems, I never overclocked it though but it worked as good as it should. Im not sure how that happened but I guess I was lucky. either that or those missing pins didnt do much. hope that helps easy your pain.