Good starter list there. I am new to the sport so I may be carrying too much but what I bring along is:
Tow rope
Dry bag (for layers)
Extra floation (10-12 pool noodles - 300+lbs of buoyancy) inside the yak (for piece of mind)
Fish finder and battery
Anchor on an anchor trolley
Kelp clip
Tackle box w/rod holders
Waterproof box with VHF radio and first aid kit
Waterproof pouches for cell phone, wallet, car keys
Sunscreen
Life vest with whistle/compass
Small cooler w/ice (lunch, snacks)
Water bottle
Leashes for all poles and paddle
Spare emergency paddle
Hand bilge pump tied to a rope inside the yak
Fishing stuff (poles, gaff, net, gloves, steel stringer, burlap sack, etc..)
Tools (pliers, knife, lip grip, etc..)
Waterproof (wetsuit) boots, splash pants
Seat, paddle (duh)
I haven't fished at night yet, but I'll probably get front and rear lights as well as cockpit rope lighting for that.
That's probably overkill on packing but I feel better being prepared even if I don't use everything. There's probably a few things I missed as well
