I seriously doubt temp affects the string material anywhere near as much as it does the bow's riser. The longer the riser, the more effect differences in temperature will have on it (one thing I don't like about the trend to very long risers and very short limbs). It will grow longer in hot weather and shorter in cold weather. Which will affect how much tension is put on the string and cables. Also, as I've pointed out before, temperature differences will have greater affect on risers machined out of aluminum billet than it will on forged or cast risers.

If you've got very few twists in your string, you will have more rotation problems with your peep thanyou will if you have a good many (20-30)twists in it. But you can overdo it with twists. I don't know what brand bow you shoot but Hoyt's recommended maximum for twists isno more than 1.2 twists per inch of bowstring.

Stay away from the rubber tubing peeps.