Re: captains license
most course work is to "pass" the test...and there is quite a bit of other that goes along with a 6-pack....insurance, documenting both your time(s), twic cards, etc, etc, etc...
were it me, and I did, I would find an active USCG-Auxilliary and JOIN and do as much as your time allows, they will welcome the wife. Their coursework and training are superb in my experience on the Northern Neck of VA and towards Richmond. You can learn everything the 6-pack classes will offer and more....and the real bonus is that there is never a shortage of experts to SHOW you or assist you. On your boat or one of theirs. I had a master chief who has probably forgotten more than I will ever know, especially as regards lines and knots. He was one of the two people I have met who can hold a line, part in left hand and part in the right hand and throw them both behind his back and come up with a bowline with a bight, and the like.
Once finished crew and coxswain, you can take even more strenuous classes with the real CG folks.
Cheaper by far this way. Down side may be, you don't have a 6-pack license, but you will have a skill set that will allow you to easily pass the 6-pack if you decide to go that route.
Others will post their thoughts as well, I am sure.
Enjoy the C-42, a wonderful boat. Be safe.