one, it sounds like you are throwing with a lot of torque. unless your beast is THRASHED, you probably will not have enough power to flatten it from a 90 degree hyzer without consistent 400+ power without torquing it up/over.
i have small hands as well, about the same as yours, mine measure 7 1/4"
i suggest consulting:
http://www.discgolfreview.com/resources ... ipit.shtml
if you are getting the placement correct, and still having trouble, then you may have your index finger at too obtuse an angle to get good pressure. keep in mind nearly every driver made after the valkyrie in late 2000 (with the exceptions of the talon and sidewinder) have extremely wide rims.
if you find yourself unable to use any grip that involves an index finger rip, i suggest using a middle finger rip grip.
if your index finger gets rubbed raw, you likely have more of a slip grip than a rip. i'm not sure what you refer to as "rip" but i'm guessing you mean an audible pop. an audible pop says nothing about your throw other than you have a tight grip, as you actually get louder pops on slips.
if you feel the need to go to a narrower disc, the teebird and eagle are 2 very good narrower discs.