We would be coming from the Beach club So we would just bring our luggage over ourselves on the boat. So how do you go from the boat dock to the check in desk?
I can only help with this one question. Sorry!
When I tried a few years ago to get on a Disney bus with my luggage to move to another resort, they told me I *had* to use Bell Services to move luggage (or drive myself.) In other words, they would not allow me to use their transportation system to take luggage from one place to another, even though I was moving from one Disney hotel to another.
Honestly, though, by the time you walk to the dock where the boat lands you could be probably halfway to the Boardwalk taking your luggage with you. Yes, then you have the other half to walk before you'd get to the dock where the boat lands, but you won't have to potentially be turned back when trying to take your luggage on the boat.
If you really want to take the boat, I'd ask (sans luggage) a Cast Member one day if there would be a problem. Then you can make your final decision ahead of time.
Regardless, from the boat dock at the Boardwalk, you'll be facing what I consider to be the "back" of the resort (honestly, it's got so many sides that I'm pretty sure that's nowhere near accurate, but it's how my brain works.) You have two choices -- the lobby where you need to check in is straight ahead of you, if your back is to the boat dock. However, it's on the second floor and you're standing at ground level. You can go straight ahead through the grass -- or follow the sidewalks around that lawn, as it's not exactly a couple of steps -- and then go up the stairs to the lobby. Or you can take the right-hand sidewalk around that lawn past the Wyland Gallery, turn right and go through a "tunnel" (past the game room on the left and the bathrooms on the right) until you come out at the fancy pool. Turn left and open the doors to go down a hall (past the gym) to the elevators, take the elevator to the 2nd floor, turn right from the elevators and walk a little bit to the lobby. The first way is certainly more direct and easy to explain, but it does mean you'll be hauling however much luggage up the stairs to the second floor.
Personally, I'd take advantage of the fact that you're going from a Disney hotel to another Disney hotel and use Bell Services. I don't know how long it would take them to get your luggage from one room to the other, but I'd rather wait on it than have to haul it around myself.