There's been a lot of misinformation (ok, some of it was just flat b.s.) posted about strings, on pretty much every message board I've ever seen. Here's my opinion, based on thousands of strings--take if for what it's worth.
For a string to twist a limb, it's going to have to be really bad, and the bow is going to have to be really touchy and/or really light in draw weight. It's not likely even a pitiful string will twist the limb on a well made bow, especially a hunting draw weight.
How the string is made will affect how noisy it is. A well made flemish or endless can be quiet, although in my experience flemish is usually quieter on a recurve.
Proper tuning and silencer placement goes a long way in quietening a string.
A nock that fits too tight, arrow spine off, or a bad release will increase noise.
A well made endless will probably be quieter than a poorly made flemish, and vice-versa.
Silencer placement goes a long way, especially on shorter/finicky bows.
Bows tillered for split but shot 3-under (or vice-versa) have a tendency to be noisier.
Chad