Nick, I agree that short courses with lots of starts will work you out and improve your boat handling. One problem with spin. cat though, if you make it a short windward leg, then downwind with the spin. is really going to be short, Put it up, gybe, take it down. So we might have to go a little more upwind if you want any time at all to practice trimming the spin going downwind. OR, we could do a bunch of short start only type courses, then after 10 starts, do a longer course for the downwind work.
Seperate exercises...
Do lots of starts and short beats and the "race" stops at the top mark; everyone then gets back for the next ineration of the start seq.
Then another exercise is the "speed" sailing;
Then some G+T exercises (gybe and tack every 20-30 seconds) on a sound signal.