I can't address your club question but I use my kayak or canoe all the time. I prefer the canoe due to the extra space but the kayak is easier to load, haul around, and to paddle. But I don't hunt out of them, I simple use them to get to my spot, then camo my position with a combination of natural material and camo netting. I hide the boat and use it for retreiving birds and decoys. But there is no reason why you couldn't hunt out of a kayak, other than the discomfort level.
You can hunt without decoys. One way is pass shooting, which I've never found productive. It mostly leads to skybusting. The other, and one of my more enjoyable ways of hunting, is jump shooting the salt marsh creeks ("criks" in south jersey) with my canoe. Only the bow paddler shoots, and does not paddle in "ducky" areas. It takes an experienced stern paddler though. I've never done this in non-tidal streams but I have friends who have, and have done well. I can't envision doing it with a kayak however. Dropping the paddle and picking up the gun when you jump a duck seems tough to me. There's little reason not to use decoys though. You can get plastic ones for little money, and very good plastic ones for a bit more. In fresh water you can get by with as few as a half dozen. I rarely use more than that on salt ponds hunting black ducks. I've lashed a decoy bag with a half dozen decoys on the stern of my kayak. My gun and the few other odds and ends fit inside well enough, but I've also learned to be a minimalist. Ignore most of the crap marketed towards hunters. It is designed to separate you from your money, not to help you get ducks.