I was just wondering how far apart your limbs tighteness would have to be in order for it to affect your shooting. For instance if the top one is 1/2 tighter then the bottom would it make a difference? Also would it matter if the bow was a single cam or double? I was just curious about this and wondered if anybody knows.

"Affect your shooting" is a pretty broad term.

Different limb bolt tightness can be a method of "tiller tuning", which some can say will provide a different holding feel and aiming characteristics of the bow. If you do a search for tiller tuning over on A.T., you'll find lots of info that you can wade through. Tiller tuning is basically slightly changing the grip angle in your hand at full draw.

But changing tiller will most definitely change your nock point setting, as you loosen the top limb the nock point moves down, and loosen the bottom limb the nock point will move up.

For single cams (or some hybrids), run a string from the top limb axle to the bottom limb axle to measure tiller as the cams may not be the same diameter so measuring to the string may provide a false result.