Great idea! Try it both ways and see which one works better for you. I tried both types of setups on my Pro Kennex. I think the 12 o'clock position worked best for me.
As for the balance and the leather grip, the leather grip will add some mass to the handle (probably in the neighborhood of 5 grams). The best way to check your balance is to balance your racquet on a dowel rod, mark the balance point, and measure it from the bottom of the handle. If it is below 13.5", it is head light. Every 1/8" represents a point, so a balance point at 13.0" would be 4 points head light, and a balance point at 12.5" would be 8 points head light.