At the moment the only (reliable) way I fount to get food (without fighting/sex) is to sleep in an Inn. There are ways to get food otherwise, but they're random, try to get the Hunger Charm (randomly fount in an over world chest) it'll reduce your food needs. Also sense I feel this'll come up, if you need gold go to the arena in the Town of Monsters (the second town). Slow, but guaranteed gold (as long as you can win, there are boss fights there).
The game is still very early release so the developer might add in playable female character, but there are other things that need/should be flushed out/finished, so don't count on it for a while.
I used bonus points and I still got achievements (though this was 02.17.0 if I remember).
Not every character is... just most... like 90+%. There is the Angel, the Orc (though you do have to fight her at least once, and she's a top). End game area the Demon Jester and Minotaur are pretty neutral to you, you can get by them without fighting/having sex. It's likely the game took some inspiration from C.O.C and T.I.T.S (both Fenoxo games).
Can't answer the quest marker question, I only 100%ed the game (as of 02.18.0).