Ok, so I will admit to having lost this battle to win the war later.
I had that strict time frame because my university project starts now and since I need that mark more than my pride, I will leave this game now as it is.
So instead of a completed game, here's a PROTOTYPE.
I leave the link to the prototype, updated screenshots and everything in this thread (so check out the first post) since it isn't finished.
Most things work though, since only three endings depend on a lot of people dying, the ten other endings do all work just fine. Male Opal definitely works in every way but the murders (they seem randomized, some people can die on all days, others just on special ones, I am not 100% sure what the issue is). So yah, you can get a few people killed, but sadly not enough to reach Ending 1, 2 and 3.
So instead of letting your mass murdering desires flow, maybe just enjoy a dating sim where you can stab some strangers in the back at night, execute your lover on your wedding day or watch your mom crying her eyes out. Or have some talks with your potential lover and be nice and harmless. I mean, it's your choice, really.
At the end of July, I will return to this (since university will be done for this term by then) and hopefully the proper game with all the deadly things that might happen will be out by August instead. Because I will definitely not abandon this, if only because Ending 3 is my favorite and I REALLY want people to see it.
So yeah, enjoy this half-finished prototype for now and maybe return to this once July is about to be over

Thanks anyway for waiting!