Also- why just say that for gyaru-chan? There hasnt been any real indication rocker chick likes girls either- I doubt rocker chicks have higher instances of lesbians than gyaru's do.
The uncle seems to know Mitsuki very well and he was rooting for her to call the gyaru. So I think is safe to assume that he knows that she likes girls. Or maybe he assumes so, but she never tried to correct him.
Just so it's clear, this has nothing to do with Nazi Germany, but with Buddhism. It's just a pun (like the ones Sugiura Ayano makes in YRYR). In fact, most younger Japanese don't even know the Nazi association.
Nazi Germany ruined forever a lot of things. The roman empire salute, the old symbol of the sun, Chaplin's moustache.
When a loop starts, a Chihaya and a Fake Ouka are created.
The only way to go to the next level is to follow the hole that the Fake Ouka created.
Once the loop ends, Fake Ouka turns into a Merrik and tags along current Chihaya, allowing her to change levels as she pleases.
I believe one Chihaya says that if you lose your Merrik you are stuck in that level.
Some Chihayas don't have Merriks, so probably they lost hers or it's her first loop.
I'll read everything again to see if I missed something.