On the breathing issue, I've concluded that I want to keep my stroke as symmetrical as possible, so I don't like to hold 2-stroke breathing pattern for very long. At the same time, a 3-stroke pattern makes my effort level go up in long open water races.
Last year I had good success experimenting with breathing patterns that mixed 2-and 3-stroke patterns. My favorite for long races was:
2 strokes (breathe on 2nd), 2 strokes (breathe on 2nd), 3 strokes (breathe on 3rd)