Hey there! I know you probably won't want to hear my opinion on this as I'm a HUGE Astarion fan, but I wanted to pop on (since it seems I'm the type of person who's currently irritating you).
I have 500+ hours in this game. I've beaten it to completion 4 times and started 8 different characters. I've done a good playthrough. An evil one. An evil urge. A resist urge. I also have over 50% of the Steam achievements.
And I have 0 issue with how you like to play your game.
I love Astarion. He's well written, well acted, and complex and dynamic. And yes, very pretty to look at.
I'm not a teenager (thank God), I'm in my early 30's and I've been playing video games since I was 4 years old.
And here's the thing: I spend hours in character creator, in all of my plathroughs, I've only not romanced Astarion once, I let him feed everytime and, guess what? I've explored every inch of Faerún.
People can play differently than you and that's okay. If a game elicits passion for the characters, that means they've created some damn good characters. You can absolutely hate Astarion; I expected more people would honestly. But in that similar vein, we can love him.
A nuanced and fun RPG gives license to people playing how they want. You can get a player who just kills Astarion right off the bat and I won't be mad at them at all. They can play how they want.
Just do what you want and avoid spaces that bother you. It's okay, man
we all support how you want to play.
