Your safety list is very complete, good job. I wish more people would put the time into it. A few things I would add. Become real familiar with how to use the MOB device on your GPS if you have that capability. Also when summer comes and the water gets warm enough practice MAN OVER BOARD drills every once in awhile they can be fun and it can save a life down the road. If you have never done that you find out how hard it is to get a person back in a boat in even choppy conditions. Learn how bring your bow up into the wind and steady it while trying to pick someone out of the water. Never leave your stern facing a rough sea as you may all end up in the water. Sport fishing boats are very easy to swamp from the stern.
Juro's idea of the epi-pen is right on be it a heart attack, bee string reaction or in our Pacific NW we have lots of Jelly fish that sting and can cause a reaction in some. As you venture further out towards the Gulf Stream you may find them there also and some barbs stuck to your flyline could cause problems for some. My wife who is a physcian put 4 of them in our med kit and every time I go in that thing for hangover relief medication I get nervous just looking at them.
Last always make a plan and let your loved ones know where you are going. If your plans change while at sea call someone and let them know. So many people leave plans with others then when they change them they never call and let them know the changes. They proceed to break down or get in trouble later the people they left the original plans with call the Coast Guard and they look where you originally said you would be and guess what you are miles away from that area drifting toward Greenland.
Best of luck with your deep water fly fishing this year.