If you identify the bend location you can make a fair job of straightening these screws using a vice and 3 blocks of wood. You'll be surprised how much bend the screws will tolerate before becoming a problem. Obviously any bend will have a little impact on the life of the screw/nut but IME even moderate bends won't affect machine performance to much and last years without any problems. I doubt you'd still have machine before it became a problem and when it does you'll be ready for changes and upgrades.

Regards the BK bearings then check the bearings are not in wrong way around which often happens. I strip every bearing to clean/re-grease then shim and every other one the bearings are in wrong way around.