3 is my favorite personally. Heavily depends on if you are looking for fun gameplay or immersive story IMO. Don’t go in expecting the most complex story known to man. I never played them as a kid and picked them up about 3 years ago and really enjoyed the entire collection.

Why write off iCloud? Just turn on the advanced data protection feature for end to end encryption.

If you want to self host, while I’m not familiar with Goodnotes I bet you could write a simple Apple shortcut to take those files to a storage provider like nextcloud then just automate that shortcut to run daily, weekly, whatever.