Yes, Selebus says she can or she wouldn't, so she can. Obviously she would not be okay with Sensei ACTUALLY being gay, but last I checked, he is not, it's just a ship, anime and manga fans of all genres and types do it all the time and only a select few get defensive about it, the rest of us just let people ship who they want. Also, yes, girls like Ami CAN be fujoshis, fujoshi means a girl that is into BL, which in all contexts is a genre of manga and anime, not necessarily the real thing whether it is real in our world or real in a fictional world like Kumon-Mi. In other words, she can be into BL and not be into real gay men, fictional tastes and real tastes can be different, mine are polar opposites.
Selebus can do what he wants, it is his game. If he feels so inclined, he can set Kumon-Mi on fire in the next reset, he probably won't do that...yet, but my point is everything is his call to make. If you can't handle that, there are plenty of other games.