Make the stiffer limb the lower limb. When you draw it gets more stress, and bering stiffer it will be stronger and hold up better.
You might try bracing it and then meauring the depth from belly to string at set distances from the center of the bow. That'll give you some idea of how far off it is. You typically want the lower limb to be 1/8"-1/4" closer to the string at the deepest point (which will be pretty close to the handel on a bendy handle bow.)
As for arrow length, its more im portant that the arrows be spined for the bow. Shortening an arrow, makes it effectively stiffer. Using a heavier point, makes it more limber. You want to play with the combination of length and point weight (if you have different weight field points that is) until you get good arrow flight, ie, the arrow doesn't slap the riser on takeoff or consistently hit left or right of where you're aiming. But yes its nice not to have arrows sticking way out front of the bow riser, so you can always get a closer-spined arrow for your draw weight to start and thatll make it more likely that they'll be of a length taht isn't too m uch out in front of the riser.
