In defense of the protagonist: unlike his father, the protagonist has an interest in the ladies' well-being (or at least dependent on his decisions) while the father himself lies, cheats, and presumably manipulates.
And just out of interest, I tried to make a list of all relevant female characters who are somehow involved with RM (both directly and indirectly):
Grace: Her father definitely has ties to RM.
Lina and Risa: In the case of Lina's stolen panties (sounds like a bad dime novel), a stranger wearing an RM mask was involved.
Rachel: Works for RM.
Evelyn and Alice: Some of their employer's ex-models are now at RM, but it's doubtful that they know about it.
Kira: She is investigating RM with the protagonist to find her friend.
Possible:
Jennifer: It is very likely that Mr. Roberts is involved with RM and if the library had gone to him, that the building would have somehow gone to those behind RM.
And of course Sakura, whose bad fake accent has been brought up several times. But I see her as more of an antagonist than a supporting character like the other ladies mentioned.
Ladies about whom we currently don't know if they are somehow involved with RM or are unlikely to be:
Monica
Fiona
Skylar
Kelly
Rose
Melanie: Has the same employer as Evelyn and Alice, but she is still well below them in the hierarchy, so it is unlikely that she knows.
Oksana: She will probably be informed to some degree, but how much she really knows is unclear. Possibly she used to be at RM herself? One of the things of her youth that she regrets (which she has hinted at)?
I've now only listed the ladies who have more than one appearance, meaning I've deliberately left out Bunny, Piper, and the woman at the art competition, since we don't even definitely know if we'll see them again. Did I forget anyone important?
Btw is it me and my vision a bit clouded by diabetes or do the school nurse and Jenny bear a very distant resemblance? If it's not just me, though, I'm thinking it's a coincidence. I think Grace would probably have commented otherwise.