RE: tightening down limb bolts question
It won't hurt anything. Put it where it is comfortable for you to shoot or gives you the best spine for the arrows you are shooting and leave it alone.
Technically a 60lb bow is meant to be shot at 60 lbs no matter what it will max out at. I highly doubt it will hurt anything though since so many people do it. I have looked at some mathews that maxed out 5 lbs above what they were rated for. I even shimmed my darton and got 68 lbs out of it. Never hurt it at all. I wouldn't suggest it though.
Most will tell you that a bow performs better when the limbs are bottomed out. I have had my bows thru the whole range and at it never seemed to effect how they shot as far as noise or accuracy.
Like I said, put it where it is comfortable to shoot and leave it alone.
Paul