Depends on the bow. If the limb tips aren't made to handle fast flite type strings, they can shear or delaminate. This is more prevalent on recurves. Most longbows and self-bows can handle it.
They generally are faster than b-50. Depending on who you listen to, anywhere from 5 to 12-15 feet per second faster than dacron on a mid weight bow, probably closer to the smaller number, but that still is equal to 2#-3# or more of draw weight. Snakeskin has virtually no affect on a bow's performance.