There are many things that can be damaged by a garage door opener. Some things once they are set never need to be looked at again, others need to be checked monthly and semi-annually. Things that if installed properly never have to be changed as long as door stays in the same place is the height of the opener from the door. If an opener is installed too high it can cause the door to bend and or crack, it can also cause unnecessary strain on the motor. Things need to be checked every 6 months are the bolts that hold the opener to the mounts, and the arm that attaches the opener to the door, that the opener is lubed properly and there isn’t any unusual slack in the chain or belt which could be a sign or gear wearing out. The monthly things you want to check are the sensors to make sure they are set properly and are tight not moving, also check the pressure switch operates properly and that the door reverses on a 2×4 set on its side.