1. I don't disagree that Jezera targeted Rowan to serve her because he's useful and unprotected, but given that the plot establishes that for a demon and a human to have children they need to love each other, something that Jezera herself mentions when asking a submissive Rowan to impregnate her in the Battle of Astarte, I wouldn't be surprised to find out that all the teasing and denial she kept playing was her way of molding him into someone worthy of being by her side, so that she wouldn't meet the same sad and lonely end that the half-breed X'zaeratl mentioned had in retrospect.
2. Funny, because I got the impression that Jezera was genuinely jealous here, hence why she felt the need to sexually humiliate Rowan and Arzyl when she (mistakenly) believed that he was going to be taken from her. Which is interesting because Jezera usually doesn't care about Rowan being married or having sex with whoever he wants, and she was up until then playing a game of teasing and denying him, but she impulsively abandoned her strategy because she was essentially afraid of losing him. Regardless of whether Jezera considered him her toy or not, I would say that her jealousy and fear of losing him were more than proven in this scene.
3. The dance scene I'm referring to is #272 in the current build.
Anyway, my point is that I believe Jezera doesn't want to have the same lonely end that the half-breed X'zaeratl mentioned had, and I think it will be revealed later that in addition to the reasons she gave for choosing Rowan to serve her, it was also because she thought he might be someone worthy of ruling, falling in love with, and having children with.