Okay, some common stuff mentioned, but here's the gist of things:
-You do have to hustle girls at times for progression, but for the most part, it's optional. It's naturally your biggest money maker though cause it's your ONLY money maker (unless you hack the game).
-NTR is avoidable, rape isn't. NTR however will lead to you losing characters for good on that run so I wouldn't do it unless you're scene hunting (and someone posted a save with the scenes anyway).
-You definitely need to see a guide for this cause some of the better stuff does take quite a bit to figure out, scenes included.
-Certain girls used for hustling do have scenes. Again, look at a guide for that cause it's one of the more tedious things to go through.
-There's loli in this game. There's also a character that looks like she could be a loli, but really isn't (as confirmed in the game).
-Get used to swapping out or even using items if you don't want a certain character to do any actions. There's no turn skips here.
-Stat scaling is kinda nuts in this game. You really don't need to be very high level if you know what you're doing but max level stats get absurdly nuts...
-Try leveling all your characters because you never know when you may need someone (or maybe you do if you read the guide).
-Alyce is best girl, don't @ me on that lol (no joke though, she does hit really hard thanks to that sniper rifle she uses)