1. A full-fledged harem has not yet been worked out. However, nothing will prevent you from having sex with different girls, but in fact at the moment they will not be able to find out about each other in any way.
2. You can turn off hunger by going to the game settings. There are also some other features that can make the game easier for you.
3. I do not observe such an error, so it is unlikely that something can be helped in this case without an accurate description of the problem.
4. This content is available as soon as you start the game. Any NPC that you see on the screen can be fucked by you, whether it's a plot NPC or a randomized one that walks around locations. No code is needed for this.
5. This is quite possible, but it requires more budget than we currently have. Any sex scene with randomized NPCs at the moment is a production hell, since we need to take into account all their appearance features. In addition, we often hold votes that affect the orientation of 18+ content, whether it is non-traditional content or something completely vulgar.