I'm gonna go way out on a limb here and say you're all silly. Some of these kits would be great for a M.F. Salmon or cataract trip, but for 98% of kayaking that's a lot of junk that can be inprovised if needed. I carry:
Spare Granola Bars
Break Down Paddle
Slings and gauze are easily improvised with a shirt(s). Duct tape will work as kerlex, ace bandage, boat fix and a million other things. For splints try a stick. As for bandaids, tylenol, neosporin and such, it's really not that hard to tough it out if you're within a few hours paddle of a car and none of that is life or death. As for purification tabs, Colorado doesn't have any bacteria in it's streams (sans confluence) that will kill you. Girardia doesn't set in for two weeks. In an emergency drink the river. I try to only bring things that will make or break someone on the river. An epi-pen and anti-histamine will be the difference for an allergic bee sting, a CPR mask and gloves will be the difference when you don't get a stranger's blood borne illness, GU will be the difference for a diabetic and a head lamp, granola bars, duct tape and leatherman will be the difference if you break gear or get lost. All this stuff fits with a camera into a small Peli-case.
For safety, all kayakers ought to carry at least two lighters as well