Having had multiple insurance claims I am a paranoid mess when leaving my house even for a couple days. As a precaution I ALWAYS shut my water off at my main valve.

For some reason after shutting off the main water supply my water dispenser has dribbled water (where you put your cup). Water pressure relief somehow allows some to come out? My house is always 72 degrees so no extreme temp issue. So I generally toss down a towel in case this occurs.

Coming back yesterday after three days (with the water shut off) I discovered a small lake of water (approx. 1 gallon) all over my floor. Upon opening my freezer I discover a large ice block at the nozzle completely icing the ice maker assembly to the wall. Tray was iced over fierce and the bin had obvious signs of run off and icing. With approx a gallon on my floor and at least a quart to a quart and a half iceberg in my freezer I am perplexed. I suspect this fourth or fifth ice maker is at fault but I cannot understand how the icemaker signaled for that much water, repeatedly and then had that much in the fridge to make that much of a mess.

Your fridge water supply should have a separate shut off valve in that line.
If you do not have one than I would install one.

Also the ice maker may not have called for a fill, it could be that the water valve is leaking.

Shutting off the mains is not a good thing as many valves actually use the water pressure to assist in sealing the valve.