Hanging in Avalon is very cool in Winter. Locals are way more pleasant, and there aren't a ton of people.
I tie up my 14 footer all the time. No hassles ever. I ALWAYS lock it up. I'v heard a few stories of them floating away. Although these stories are not common, I still protect my stuff.
Shore boat is $4 each way. Yep, ouch. If you need the service, drop off everyone at the pier, and go park the boat solo. You'll save $8 per person. That's more Mai Tais.