TJ -
Your description of the battery setup is identical to mine, including the gel cell for the kicker that is not wired to the others.
Your other two batteries that are charged through the switch by the big Honda should both be the same size/type if you ever plan to charge them both at once. Les says the marine cranking batteries are great, and that they are sort of a step between a deep cycle and a starter. My setup has one battery for the Honda 130, and the other for the house. I have a battery combiner wired between the two (
the 50 amp model of this), so when either one reaches a voltage of 13.something, indicating it is being charged, the combiner switches itself on and parallels the two batteries. That way they both get charged whether running the motor or using the on board battery charger. Some folks don't like the combiners, but I love 'em. It has always worked for me. The only thing I use the 1-2-All switch for is to disconnect the battery from the motor when left sitting for any length of time.
Your fridge will probably have the automatic switch over to AC if the shore power is plugged in. Mine is strictly DC, but when the shore power is on, the battery charger is also going, so the AC switchover is not needed. If for some reason I want to run the fridge on AC separately from the shore power, I have a little converter that I can plug it into. I have run the fridge for a good 12 hours without recharging the battery several times, and it never is a problem.
I think the gel cell (mine is actually an Optima spiral wound) for the kicker is great. It will sit for much longer periods without a recharge than a lead acid type, and generally takes a lot more abuse. But it is sitting right there for use as a jumper battery if ever needed. The chance of needing it is so slight that providing the wiring to let it switch over to the other system is a waste of time. If I ever need it, I can swap the positive cable to it in less than a minute.
Congratulations on your new boat! Let me know when you want a photo album for it, because we gotta see the pictures!