I think that first part only works if Kiriya is into women which it doesn't seem she is so far and the first half second part seems more likely as you can tell the MC doesn't think of himself as "main character" materialNow question is is he gonna try keeping the mc the same in his vision and make it yuri. Or he gonna find new mc/or himself as lead.
Not really, it's just a matter of identities, you can only pay stuff around there if you are a student, her student persona is a dude, so the system won't recognize her, that's why mc had to pay for her, she will meet him later on as a dude to pay him backhis thoughts on different personalities, and her directly stating "the other me", I have to assume she has split personalities.