Transition to SDL2 is now done more or less. There are some minor issues with keyboard (scancode confusion) and the way window background was saved and restored in previous version. Shortly described window backgrounds are not saved so the background is trashed. It can be fixed by drawing everything that was in the background.
Other than that I've done some good progress by cleaning up a lot of classes, sort of checking out them again to reduce "things to fix". I'm also starting to get a good idea where the most work should be concentrated which are fine details of level generation and RPG system as a whole.
The RPG system is the biggest problem I have in this project, because well.. it doesn't exist. Or it does in some sort of vague form with some random stats and stuff. But you need lot more than that for a working role-playing system. I did make a big mistake by trying to create it starting from the "wrong end" which means adding lots of stuff without knowing how they play together.