I have the closed circuit engine cooling feature on my boat. I will have easy access to the boat this winter and may use the boat when we get those occasional warm winter days.

Last year with indoor storage, all I did for winterizing was drain the heat exchangers, add fuel stabilizer and put anti-freeze in the water tank for the boat to sit up for only 60 or so days. Is there anything more I should do to winterize the boat if I plan on taking it out some this winter?

The boat lifts out of the water enough to where only the skeg and prop is touching the water with the drive down.
After it sits for a while and the drive drains, should I raise it up?

Seems too easy. Am I missing anything? Thanks,

If you have power steering and/or oil coolers, make sure they're drained. I didn't see "risers" in your post, those too. If all that drains with the exchangers, I'd say you're good on the draining.

But--check your outdrive for water. Just unscrew the bottom plug, and let a little fluid out. If there's any water, it'll come out first. If just lube comes out, you're fine, tighten the screw back up!

Thats something I have not done yet.

First winter with the Party Cruiser, I oops'd and didn't drain the lower unit. In March, I found out the hard way that the lower was taking on water. The water froze, and pushed the prop shaft bearing carrier out, breaking its mounting tabs and bending the studs. The ice also pushed the oil seal out of the carrier. I'm lucky the lower unit housing didn't break. (the carrier that broke was brand new, the old one is on the right, and has been in it since.)

Update: Per the Mercury manual. Leave the drive down for storage. Damage can occur to the bellows if left up for an extended period of time.

Yeah and if you leave the drive up it also stretches out your shift cable boot. My friend learned that the hard way. He had an older shift cable and never had it in the 'trailer' position but he was changing props in the water and decided to do it the next day. I get a call saying his boat sank and we have to pull it out. Later we come to find out it was his shift cable that had ripped. Only took a short time to sink that boat and now we have to completely strip it and start over. So that was my long story as to not leave your drive up or at least do regular maint. lol.