I do not know the answers to your question although I know about the importants of the right safety equipment.
My wife got a hole in her kayak while we were out at catalina fishing. It was not a problem because we had a hand held bilge pump and were easily able to pump the water out and get to shore. Kayaks won't sink quickly if at all so you have time to get the water out. We also had a VHF radio to call for help. A map of the area to communicate where we were and also a GPS to give exact location. We got a ride home from harbor patrol in a reasonable amount of time to enjoy the rest of the day and never felt we were not safe.
I also carry:
A small 1st aid kit
Extra water and dry food snacks
Flashlight, whistle and signaling device (mirror)
An extra paddle (I once lost mine on the water, it sucked calling for help because I lost my paddle
. Now I keep an extra in my yak.)
Also keep your PDF on, gets hard on hot days although if you are forced to go in the water you do want to float.
Also note Kayaks are super durable. Her kayak was over 6 years old and was given some abuse on long road trips through mexico. In 6 years it was dragged to and through more beaches than I can count. Wheels might be a good purchase too to limit dragging the kayak.
- Joe