Re: US Sailing vs. ASA courses, vs. just get out there
Regardless of the quality of instruction, you are going to need to do two things to be a good (safe) sailor:
1) Sail a lot. On a variety of boats with many experienced sailors.
2) Keep pressing for more information from all sources possible: books, internet, sailors, etc.
Regarding USSailing vs ASA? Don't know. Probably doesn't matter as much as the individual instructor.