Version 1.1.2 prevents paintings from being placed, and when using mods that allows for painting selection, no painting options appear at all. I tested with only this mod, Farmer's Delight, and Brewin' and Chewin', and the issue persisted, so it's caused by this mod. This problem only occurs in the latest version, paintings were working correctly in version 1.1.1.

Yeah, probably because there is an unused painting in the files, probably gums up some junk. Will be fixed in the next patch.

Will be fixed in 1.1.3. A push has been made which implements the unfinished painting, which should fix the issue.