Jake,
if I understand you correctly, you dont go out to train but let racing do as your training?
I think that is a very good way make it difficult for yourself. With your mind busy on other boats, strategy, marks etc. you will not be able to focus on the simple things that you dont do well and correct them. Regular training sessions, where you have identified one or two weak points you need to work on before you go out on the water, is really neccesary.
Using racing as training is fine as long as your head is in it the right way, and you race often enough.
We race every week. When I was beginning in the Fleet I would concentrate on one area of performance for a number of races or even a whole series, then switch to the another area. Feeling out the skill area is primary, getting a trophy spot becomes secondary as a goal, and you have other boats on the water to gauge your progress by (whether one design or not). We'd also use pre start time to just do as many tacks and jibes as possible, and after the race do a little more of that or just pick a point and try different things to see how the boat responds. The skills accumulate, and even though the trophies aren't goal you end up with some of them too.
Still probably not as effective as two boat testing and intensive drills, but most can't free up that time.
