IMHO, all characters preferences should be randomized so that way not everyone would fit with everyone else.

Explanation : I roll a Human warrior, then computer rolls the NPCs for my game.

1 is homosexual, 2 are straight, and 2 are bisexual.

next game I roll a dwarf cleric and everyone is homosexual;
next game I roll a drow ranger everyone is straight..;
this way, no one would know who he/she/it can romance and the romance game part would be more interesting. I want to romance Shadowheart, but halas she's straight and my character is female.... Damn... I have to forget this until maybe my next playthrough...

Who the hell cares? why would everyone be atracted to you? Who the hell are you?
Replayability? No one seems to understand that many RPG players are actually rolling multiple different characters with different ways of playing.

One playthough where I can romance all characters? Not needed, more, why would anyone want that!

What we need is something that tells the player that he/she is NOT THE MESSIAH and not everyone will like him/her + not everyone will want to have sex with him/her

That's a bit odd to call for sexual intercourse when the characters you deal with in your party knows you for 3-4 days and hasn't been in your party at all... I look at you Astarion, I don't use him much I prefer spell casters over anyone else. And Running water kills you anyway: you little shit.

Maybe there could be limitations in term of CHA or Reputation or maybe STR who cares?

My human Warrior is 17 str and 8 CHA, but this character only likes 16CHA PC, ok fair enough I'll pass then. But another Character is really attracted to me because my STR is higher than 15 and therefore as the prerequisite is met I can.

Also DROWS must be racist... Racism is essential in a world like the Forgotten Realms. Half-Elves aren't humans but they aren't elves either, so every dislike them because they're not pure bred... That's normal!

Racism isn't that bad... People always have preferences, or else the humanity would all look the same.

We are social animals, but animals still, we have something in our brain that commands our sexuality, that's not SOMETHING YOU CHOSE ! Hence if it's not something you chose, then non player character sexuality should be randomized...

Come tell me otherwise LGBT+ people smile