Well if that's the case why not put that in the overview? Or heck make it a female protag. Why have a mc in the first place? or maybe in developer notes. If that's really the case the overview doesn't make sense.
It's not in the overview because it wouldn't fit there at all. Actually I think many of your questions here are easily answered given some thought.
The player character is the one you control, but he is not the hero or protagonist. Not that I would do it, but the player character could die and the story could easily go on. It couldn't start, but it could eventually go on.
He's meant to be a normal (horny) guy with the ability to do normal things. It's your rare encouragement and support to these women that inspire them to do things. It was my goal to make the reader emotionally attached to each female protagonist, not the player's character, because Harem Hotel is about these main female characters that some people might be able to connect to.
I can't comment directly on his thoughts since I never saw him mention that, but from my own perspective: the MC is the catalyst for much, if not all in some cases, of the changes the girls go through. Either by providing the support, encouragement, money or backbone he's the lynch pin for much of everything (and likely much more). The game I'm sure has grown from what was originally planned in some aspects, so just tossing the MC out to the curb after all this time would require significant changes to the story that currently exists.
While I'm not sure on the context of "the game being about the girls and not the MC", he is still a very valuable element and contributes to each girl's story.
This story wouldn't have happened without MC, it starts with him and his hotel. If he weren't as supportive, the women wouldn't all stick around, and the harem wouldn't have happened, etc etc. It's his ability to support that makes him special I suppose. I mean he is able to consistently take care of 8 girlfriends needs and inspire them to do great things. He doesn't have any issues, he's the perfect person for this society actually. If his story is anything, it's one happening in the background.