Not really, normally it's a lot worse, just look at all mangas and doujins with rape here and you'll see this is not rape at all, and I have read one manga with real yuri rape recently, it had blood and was worse than all rape here on Dynasty.
Hmm. Never see them as a pair but a partner though. Since the anime doesn't show them together that much. And recently mikuru is not around in the anime after WM ended.
Though this two doesn't have that much appearances... I can feel a Yuri vibes with them. Mikuru improving herself to be a deserving partner to Mizuki. They are living together just what Sena and Ichigo said they looks like a Married couple. I like also the Aura of Mizuki when she is with Mikuru. For me, this two is a good pair.