Think about what goes into a kit to temporarily fix the blind. Depending what it is, I have found them to be susceptible to damage from dogs and 300lb hunting buddies - a few ratchet straps, a bag of zip-ties and a broom-handle can save the day! think about a place that the dog can see out of and sit safely (assuming you gain access to a dog!). If the dog is regular fixture, consider a boarding ladder. I have a "load-a-pup" - very nice product and very helpful with only a small amount of training for pup to learn to use it. Check out the inside of the boat for slipperiness, and take steps to improve traction if necessary. It's one thing to fall down when you're fishing and everyone point and laughs and says "FAIL"! Falling down with a gun is not as funny... Let's see... what else. Oh, have TWO anchors. Very handy to keep you firmly in place. Sucks to be swinging around on one anchor and screwing up your shooting angles when the ducks come. I also made a VERY handy pushpole out of an 8 foot 1 1/4" curtain rod that I attached a pvc "T" to the top of. I cut the side off the top of the "T" so that it made an excellent pushpole for shallow water. I see you already have a spare tire, so that's good. Aside from that - the usual "tips" for waterfolwing still hold: do your scouting, hunt where the ducks want to be, get there early... Account for enough time to find your spot in the dark (going before in daylight with a GPS and some reflective flagging tape can be handy). Mark channels and obstacles on your GPS as necessary. Also a great idea to have a second spot in mind for that day when someone gets there first, or is set up too closer than safety or etiquette rules suggest you should drop anchor. I also really like the waist-belt inflatable PFDs. they're obviously not as safe as a "real" one (you have to pull the cord yourself, and then pull the thing over your head like on the airplane safety videos), but they are a lot safer in the long run because you tend to LEAVE THEM ON! They serve as a good wading belt anyways. My waist one stays on the whole time. I put my collar-pfd on for the ride out/back, but take it off for unconstrained shooting. Oars or at least paddles of course, along with all the other required boating kit. You'll be out in the dark, so you'll need some nav lights to be legal i think. I bought clamp-on battery operated ones and broke the clamps the first time out. Replaced teh clamps with cheap carpentry spring clamps. They run on a pair of D-cells. They're "just ok", but cover your ass, legally speaking , on your way to the blind and back. OH, and one of those manual bilge pumps that people use in kayaks (red and black things that look like a bicycle pump from Canadian tire) - it's AMAZING how much water a lab can bring into a boat! Very handy to pump it out. I also made two plywood floor panels that I put down between the back/middle and middle/bow seats. I cut notches in them to marry to the ribs in side the boat, to hold them solidly in place, shored them up in such a way that they're approximately level, and applied anti-slip compound. that's where myself and the other gunner sit, on swivel buckets (not on the boat seats themselves). mine is only 14 foot, but I still think that you will probably only want two guns in your boat. A third guy might be OK if he stays back by the "drivers seat" out of the way of the action, but probably not three guys shooting at once. I might be wrong on that.
Congrats on the boat. Have fun and be safe!
-Dave