"Running the freshwater pump long enough to pump out the tanks entirely will take a long time."
A 2 inch sea cock in the tank ,,dumping the water into the bilge' will allow poor quality water sometimes taken aboard to be quickly dumped when a better water becomes available.
The tanks stay full at the dock and I can fill them from inside the boat.
There is a gallon meter that will stop the boat from sinking (if anyone has links to a better one please let me know!)
Pressure regulator is built into the Shurflo water entry (get it from Amazon - waaaay cheaper)
I added creature comforts like an undercounter water filter and hot and cold water dispenser (also Amazon)
I ended up using braided vinyl. I thought PEX would be 'more professional' but no one carries a full line of fittings. The vinyl is easier to move around though anyway.
It takes the same amount of time to disconnect the water as it does to disconnect shore power. The hose, filter and gallon meter do take up more room than just the hose. There is still plenty of room to stash it all in the flybridge when we go on trips.
Thanks everyone for your help in getting me thinking about all the things I needed to think about.