More evil as he goes on. Starts wanting to fuck girls who called him "weak", ends up with wanting to cause chaos just for the sake of it. It IS meant as part of the story, and it's pretty clear it's meant to be presented as despicable since the entire 2nd Route works off of that.
2nd Route is True Harem. If you never lose, the girls will only experience the MC and only him.
The MC himself is a monster who can turn into either "Humanoid" or "Tentacle" forms. In the 1st Route, YOU are the one who can assault girls in battle when they're weak enough, or during the story as part of the main chapters. "Multiple Penetration" is referred to the tentacle parts. I know what you meant with the "everything that can fuck, fuck your girls", and the answer is no, it's not that kind of game. YOU are the monster who fucks, basically.
Game is... Embarrassingly easy on "Easy" (duh, lol). Just go beat some monsters in the high level areas, reincarnate into some high level monster, and level it up again by beating - again - some monsters in the later areas and you'll be spamming the normal attack to win every battle. To test the "battles where you have to lose", on Easy, I literally got bored since after 5 minutes I couldn't die even if I wanted to.
Actually I only experienced that once, and before uploading this game too, when I was quickly checking if I spaced a text line correctly. I just put it there ot be thorough, but I honestly don't think anyone will ever experience it, it could have just been my PC having too many programs open, making an out of memory exception ahah
There is, but it requires for you to beat the story. Right up the stairs, there's two "objects" on the right in the recollection room. Beat the "Evil Route" to be able to unlock all its scenes, and then beat the "Good Route" to be able to unlock everything.
No clue what Pronant Symphony is, I'm afraid. I may be biased since I worked with this game for half a year, but I loved how the game "gets real" later on. Won't say much because of spoilers, obviously, but I really found some side-stories to be quite sweet, or to actually carry a pretty good message.