First is the engine raw water cooled or closed cooled (heat exchanger?). If closed cooled, that's OK if raw water cooled, it might not be.......
I'd be most concerned about the 'circulating af for 10 min'. I have commented on this many times, if the engine does not get hot enough to open the thermostat, or if they did not drain the engine first or remove the thermostat, raw water can remain in the engine and freeze. That will crack the block and then it's new engine time. I don't think there is a -40 AF, only -50, -60 and -100. This is a lazy man's shortcut. Yes the marinas can do it when they do 100s of boats, and have a trough to run the drive in, which re-circulates the AF and it stays hot so the thermo will stay open. If you don't know for sure if the thermo opened, it's risky. The RIGHT way is to remove the drain plugs, and probe the opening with a long wood screw, awl or thin screwdriver to drain all the water. Then you can back fill with AF through the hoses, till a bit of AF comes out the drains. Then put some gasket sealer or marine grease on the threads of the drain plugs, replace them and continue filling till the engine and manifolds are full. I would pull the engine block drain on each side, and let what's in there drain into a paper cup. Put it in the freezer and see what happens. If it freezes drain the block completely.
I ranted about this on the
http://www.boatingabc.com board about a month ago. Somebody had a boat with a Volvo engine, did it that way for years without a problem. BUT, I bet he never knew how close he came to freezing the block, just lucky. Well he got another boat with twin Mercs, and did it the same way. Because of my rant, he checked the block drains and pure water came out. So not all engines will warm up enough, to get the thermo all the way open. Lucky he listened to me, he would have needed 2 new blocks come spring.
Oh and yes the gear oil should be changed and the steering ram greased.
If you want low maintenance don't buy a sterndrive. They have some good points but low maintenance is not one of them. Low maintenance = outboards.