I have done a few head gasket jobs. I usually clean with brake clean and brush. Clean/lube bolts with oil (also apply a little bit of oil where the head of the bolt contact area to the engine head). I have never seen/used antiseize on head bolts ( I don't know if its good/bad to do, just never have heard about it). The main reason of oiling the threads, among other reasons, is to properly torque with lowest friction as possible. Reusing head bolts is fine as long as its within specs (that why the engineers who designed the cars have given you these specs).I have never used a tap to clean the threads myself, but as long as you use the correct size, probably wouldn't hurt. Although, in my experience, I have had taps break (without excessive pressure being used) while cleaning threads on other parts of vehicles. Wouldn't that suck getting a broken tap out of a head.Hopefully some of this information helps. Good luck.