The peasants thing is because I always see Rina as Royalty, like she's above everything and common people matters don't affect her. It's basically a meme thing :)) Even when they dress them as school girls and each uniform is different (for performances, not as much for robosan) Rina's uniform is by far the most expensive looking one.
The plot is definitely getting thicker (or at least more plot-like)!
Spoiler:
I caught some of what was going on (mostly by stopping/replaying/checking words in WinJDIC), although I know I missed a lot. This raises some interesing questions -- I'd guess that it's no coincidence that the girls picked the robot's control room as their hangout, for one thing. And of course, this could bring in all kinds of time loops and paradoxes. Aaaaaaannnnnnd....... Robot pilots in the future sure have nice looking white boots. :))
Aaaaaaaannnnnnnd.... (Spoilered for serious speculative spoilification)
Spoiler:
It sounds to me as if Mayama's character is destined to be Dr. Tachibana's future daughter-in-law, and Rina's mother...