Swim - do as much as you need to feel confident and strong in chop and swell. Could be very little if you're already a confident swimmer, or quite a bit if not.
Bike - same thing in a way. Do lots of hills in training until you feel at an advantage on a hilly course.
Run - no need to go mad. By the time you get to the run on race day it's uncharted waters. Better to get to the start uninjured than to make the whole thing impossible/miserable by having done too many long runs in training.
I agree with decadave on all points except Winging it - Wales doesn't take too kindly to that approach!
Great race reports, all, and some incredibly gutsy performances.
FF, it's not Raynauds, but I had the same at a hot, humid IM (did you also have headaches and light-headedness?). I think it's hyponatraemia due to drinking relatively too much water and not enough sodium/salts. Having to pee every few minutes afterwards kind of confirmed the diagnosis! Well done for hanging on in there.
Don't be afraid to give your club rides a try. Sitting on other people's wheels can give you another 2mph.
And so what if you get dropped? It happens to everyone, you just need to figure out a way to get back on your own. If you give yourself a trial ride, planning to get dropped, you'll probably surprise yourself!