As long as you do not exceed the elastic limit of the bolt or nut you can torque and retorque forever. Torque to yield bolts are designed to exceed that limit and should not be reused. I have never heard of a rod bolt being TTY.

Not a problem. there are some that believe cycling the nut on a bolt several times before final torque makes for a more accurate torquing in the end. I dunno if this is because they think it burnishes the threads or what, but it isn't an issue regardless.