To add some thoughts about upwind settings/rig tune:
-Rig tune is not a "set it and forget it" proposition. I use different settings for about every 3 knots of difference in breeze. Make sure in 12-15 you are at about 39/39 or slightly less on the Loos gauge-it will make a huge difference in your ability to flatten the main. If you are light on crew, go slightly tighter to keep the boat on its feet.
-Outhaul should be pretty tight in most conditions. I only ease it substantially in very light or very choppy conditions. If the outhaul is too loose, you will definitely bubble the main when the jib is properly trimmed.
-we carry the class 163 genoa and trim it to about 2" off the shrouds/spreaders and don't have any issues with backwinding the main. Make sure your traveler is on centerline and the mainsheet is very tight (especially above 12 knots of breeze)-your top leech telltale on the main should be stalled about half the time.
My basic advice is to trim the jib tightly to maximize point and then play with all the adjustments on on the main to get it driving properly. NEVER sail below your highest point as indicated by the jib luff telltales-you are sailing an enormous amount of extra distance if you sail too low. I usually try to get my windward jib telltales to "bounce" a bit (i.e. stall just slightly) once the boat is up to full speed.
