I do most of the winterizing that was mentioned, just a little differently.
First up, clean the boat inside and out. Vacuum out the inside, wash the outside and remove everything that isn't anchored down. If there is no mice food or bedding material, you are less likely to draw mice. Pulling everything out of the boat and moving it to the man-cave gives me all winter to respool reels, clean reels, tie up new jigs, sort/clean/organize my tackle boxes, repair/replace worn items, etc. I don't have to keep going back out to the boat all winter long.
I add Stabil to my gas tank during each fill-up. Never have to worry about adding it before winter or running it through the engine. It's already there. I try to top off the gas tank before the last fishing trip of the season. I prefer to store it with a full tank of gas.
I fog my engine, however I pull the spark plugs and spray the fogging oil in each piston chamber. I rotate the motor (in gear) by hand while spraying. This gets the oil where it needs to go and doesn't foul out my plugs. Not that foul plugs are a problem. I replace them every year. It's two plugs at $5-$6 each. Cheap maintenance.
I replace the lower unit oil for several reasons. 1) I check for water in my lower unit. If I have water, I have all winter to replace the seals. 2) If I left the water in the lower unit, it could freeze and crack my lower unit housing. 3) Motor is ready to go in the spring, no further maintenance needed.
While I am down there, I also pull the prop and look for fishing line. It will eat seals in no time. I do the same for the trolling motor.
As for water in the cooling system. By spinning the motor by hand I am turning the impeller. Any water left in the system drains out the intake holes. I am not running the motor and don't need muffs pumping water into the system. This leaves the fill holes open to the intake ports and drains the impeller housing. Leave the motor in the down position so water doesn't collect in the hub area.
One last comment. Running your motor until it is out of gas does not burn the gas in the carburetor fuel bowl. That fuel stays there all winter unless you specifically drain the bowl. Gasoline WILL gum up and leave varnish plugging the jets. Leading to a carb rebuild. Either drain the fuel from the bowl, or add stabilizer to the fuel to prevent gum/varnish build up. While most don't like ethanol. It does have the advantage of cleaning out gasoline gum/varnish deposits. Ethanol will keep your fuel system clean and gum/varnish free. Yes, I prefer ethanol blended fuels. If you want to debate ethanol, start another thread. Don't plug up this guys thread with that conversation.
I do pull my main battery and move it to the garage so I can keep it on a charger all winter. No on-board charger for the main battery. My boat lives under a lean-to attached to my shed all winter. Lean-to has a roof, but no sides and no heat. I also run a cord out to the on-board charger to keep my trolling motor batteries charged all winter. I also top off my batteries fluid levels. Make sure you use distilled water.
Now that my boat is winterized, in the spring. Drop in the main battery, check tire pressure on the trailer tires (look for dry rot or side wall cracking while your there), hook up, load my fishing gear and go fishing. If the trailer tires show signs of dry rot, or sidewall cracking, replace immediately. Trailer tires only last for 5-6 years. Do not go by tread wear. The rubber breaks down and your only clue is sidewall cracking. The sidewall carries the load. Fastest way to end a fishing trip is a blow out before you get to the ramp.
Seems like a lot, however when the ice is off the lake, I'm on the water. Been known to tent camp and fish with air temps in the 30's.