It isn't coloring my views at all, Sebastian is simply a huge hypocrite when it comes to being romanced by Hawke. Yes he does, he calls her out, if she tries to romance him, as having given away her virginity already even if she gave it away before meeting or flirting with him. Sebastian has no room to talk as he's no virgin and has quite the history, he also doesn't ever suggest that Hawke could do what he did, and do the whole "born again" excuse, so that they could be together.
That's incorrect, if Hawke has sex or even flirts throughout DA2, even prior to meeting Sebastian or flirting with him, he will know and push her away without a seconds thought. Thus proving his hypocrisy as he's no virgin when he "found the Maker" or when he meets Hawke.
It's okay for him to be purified in the Makers eyes but it isn't for Hawke as far as Sebastian is concerned. Furthermore Sebastian will still betray you, even if you romanced him, and threatens to raze an entire city. He doesn't once consider Hawke's thoughts on killing Anders or that Hawke may want to put Anders on an official trial thus taking away the Marty angle that Anders wanted.
It is indeed demanding as Hawke can bend over backgrounds for him and, like I said repeatedly, he will not even consider anything, relationship-wise, with Hawke if Hawke isn't pure and ready to be fully dedicated to only him while he wont to her(As he will never even entertain having sex with her even when he knows that she wants their relationship to become fully intimate).
Rival Sebastian was pushed to go away from the strict Chantry teachings and he even breaks his vows to the Maker if he goes to reclaim his home, yet he doesn't do the same when it comes to sex. That's a mockery of the Chantry's teachings as Sebastian is selectively choosing which parts to obey and which to ignore thus revealing that he isn't a devoted servant to the Maker as he harps about.
In the end Sebastian never should have been made a romance at all. The only reason he isn't into sex, or breaking that part of his vows unlike the other parts he breaks for a personal vendetta, is because he wasn't getting a romance scene. He doesn't even kiss or embrace Hawke! Thus by cutting corners, and making him a romance anyway, he comes off as inconsistent and a hypocrite.