1. It's for romance routes. For now you can only get 2 hearts with Bernard and 1 with Arion.
2. Nothing at this point will happen. In future? Probably some romantic story progression with certain character.
3. For the same reason as you can't have 100 like or 5 hearts with everyone. The game is still a WIP, so not everything is finished. Also Arion is written not by me, so I'm not sure what are the exact plans for this character.
4. Isn't the whole game a harem route? :P
5. I don't know. I could go with few, I could go with dozens. Depends on people really, how much they are going to enjoy the game and how much more would they want to see.
6. Yes, there will be an end. Eventually. I could go to the finish quicker, but I can also fill the game with side stories (Like with the lizard).
7. There will be more interactions between characters.
8. I'm trying to put different variations how to end certain sidestories. I'm not sure it's always going to be good/bad ending, but I'm sure I'll add different variations.
With more beasty opponents there is a hidden variable. If you submit to wolves, raptor's corrupted lizards then that variable is going up. if it's high enough then additional things are unlocked.