Is there a negative effect (other than puling the threads) to tightening down cylinder head a little tighter than honda specs.

Honda says 72ft lbs. Mine was tightened to 80.

 

you are going to risk damaging the threads and warping the head or block, I think your going to be ok though.
Did you measure it as you were removing the head bolts? Removal torque is always higher than tightening torque.

 

I always go with what Honda says. I got myself a nice torque wrench so no probs there ...