Why the fascination with ultralight? You've got a kayak to carry your stuff, and even 5# of survival kit is going to be less than about 3% of the total weight of you, your boat, and anything else on board -- you will never notice the difference. With an ultralight mindset, you're going to be stuck wanting most times, and for no real reason when you can easily carry normal things that will actually solve a problem well beyond the "I'll just have to make do" stage.
I'm an EMT and a few other related things, so the lists beyond the first one are perhaps a bit over the top for most people, but I think everyone should have what's in the first list at an absolute minimum.
Here's what I carry on a quick (2-4 hour) hop.
On more involved trips, including anything on the open ocean, I add to that.
On my spray skirt is a strobe light. If I'm paddling at dusk/night, I have navigation lights fore and aft. Clothing goes in dry bags, and keys/wallet/phone goes in a dry box. Food goes into whatever makes sense. Some in boxes, some in bags, some in their own packaging -- bottles of juice, etc.
I think everyone should practice "what if" drills. Practice capsizing, bailing out the boat, then getting back in. Practice helping your kayaking buddy while you're in your boat, and in the water. I do this every year without fail. On a super hot summer day, "practice" whenever you want to cool off a bit -- it's a nice and easy way to keep your skills sharp.