We binged 13 episodes back to back, so I've seen all 15 now. It's like a Chinese Hollyoaks.
I think Gu Hai is a total weirdo, and they've foreshadowed what he becomes quite well. If he doesn't get his way, he will hurt you into submission (old school definition of that word) so you do it.
I don't think the season did a good job showing how manipulative Gu Hai is. From the book he intentionally calculated that pushing Bai's Dad towards their Aunt will make Bai feel lonely, and that would be how he can worm his way in. In the series it just looks like coincidence it all happens, though they could
reveal Gu Hai planned the whole thing after he rapes Bai.
From the spoilers I read online, Episodes 16, 17 and 18 would have been the most controversial episodes, so makes sense they're holding on to them until Season 2.
Poor #TeamCW, feel free to add me to his loser squad of 1.