It's all personal opinion and experience of course. Based on patch 6.
The problem is, the required approval threshold is very low right now (Medium, only a step above Neutral, which everyone starts at) and it's very easy to get everyone to that level.
Yes and no. I did the goblin fight and the defense of the grove fairly early in the game (talking of Minthara, deceiving her felt good!). Medium threshold is the best I could hope so early in game.
My drow has been rejected by Lae'zel and Astarion (and he had Medium approval with the latter and donated a bit of his blood; he had no illithid dreams or encountered the hunter at that point, though). Surprisingly, he did get an offer from Gale and Wyll (despite both being Neutral). However, my drow had quite the chemistry with Shadowheart from their first dialogues. And yes, you can fairly easy mess it up as the outcome from your "date" with SH depends on an insight check. It is at times confusing but I admit I did not find anything too unrealistic about it. Especially taking into account the amount of alcohol being spilled.
I do agree that that party should not be the only place where you can start a romance.
I think only Shadowheart and Wyll act like adults if you don't pick them. This way of structuring dialogue makes it seem like everyone wants a piece of you even if they actually don't.
Nothing from this surprises me. Gale has quite the ego, Astarion is... well, Astarion
and Lae'zel is also very prideful.
