1) more monsters are being gradually added, and previous monsters are being updated. I'm sure Nono's got a lot of work to do, so don't rush them too much.
2) for me, scenes sometimes freeze for about a second or two, but only on tentacles whose bond scenes aren't complete. I assume this is because they aren't complete, and the problem will be fixed once the full bond scenes are finished. If your freezing problem is different, you could be more specific
3) other comments have noted disappearing monsters between updates when trying to swap save files between updates, but supposedly the problem was fixed when they reinstalled the game
4) not quite sure what you mean by this one? maybe check to see if your save directory folder is still there?