Astarion is not sincere when you talk to him usually, you get medium approval and he says "oh youre my best friend" almost sarcastically. I shouldnt need to point out why Astarion is more modern, if every character wasnt pansexual, everyone would assume Astarion is gay. Gale has very modern sense of humour and approves of a lot of evil player actions even though he gives a different impression.
I don't know, and I don't even want to know. I want to discover.
You can go to Jaheira's house and you'll learn her history and they talk about her being old all the time, she calls you a "cub" (sees you as a kid).
Is it because when a woman shows less respect and devotion she seems more exciting?
Why would everyone be automatically devoted? People want characters with depth of personality, not a predictable doll, someone with their own desires and opinions. Yes those characters are more exciting and people dont want to auto-win the relationship, you should need to work for it to feel it's rewarding.
On other hand i recommend Dragon Age 2 romance, you can romance characters with maximum negative approval - actually its a different system and its called rivalry and you get a different romance if you go that way. But you can criticize and disagree with them on everything, it's pretty good.