I fish from a sit-in, sometimes-closed kayak, and can't say enough good things about it.
You're right -- keep stuff off the deck, not just to clear the way for your fly line, but in case you go over. I haven't had it happen yet, but I constantly plan for it, which is the only way to fly.
It's funny about the line; I sometimes let it lie on a closed cockpit, and it doesn't get tangled there. But I often just make sure there's no water bottle nor bag lying in the way, and let the line coil up inside, where it is usually wet and the chances of line catching on your legs is about nil.
Anyway, fishing from a kayak is a blast in itself. I could get ten motor rigs if you gave me a couple days to liquidate, but won't -- yet. I like the ease and lightness and portability and immediacy of the kayak.
I follow the norcal board too, and post a few things about kayak fishing on my own
lil blog too.