Kay so I figured it's high time someone got some tips and tricks going, I'll share what I know.
-Characters have motivation states. If high, they'll be signaled by a green smiley face on their status screen. You can keep it that way by talking to them, letting some time pass without deploying them with the team, or feeding them. More on that later.
-Characters gain bonuses by becoming enamored with the MC. You can get anyone up to infatuated just by talking to them. That's a small but fairly significant boost to their stats. Further states give better boosts.
-For sheer firepower and agility nothing beats chicken weapons. You can obtain them by buying aberrant eggs, which you gain by recruiting Roten Egg/Ten. He's the yellow kid with an eggshell on his head. To recruit him, you need to find and beat him.
-Random events in between battles (when the exploration gauge fills up) are always either fights with anomalies or wanderers. Wanderers are dungeon merchants or new characters you can recruit, almost always by beating them up.
-Each character has a key item associated with them that provides a bonus of some sort the more you collect. Chief/Shitsuchou gives you bonuses to speechcraft exp at random, for example. Some of these bonuses are REALLY useful.
-Apparently Luck is supposed to be an important stat for finding rare/good stuff. I've only found one way to boost it and that is by resetting sex morals/stamina/something else in the kitchen. Out of those Stamina is one of the least troublesome once you have enough money because you can make aphrodisiacs to give yourself more arousal.
-You can cook as many times as you can afford. Pretty much every food has aphrodisiacs laced in them (thus increasing estrus and your sexual stamina). You can also masturbate onto the food, which you can use to make other characters into semen addicts apparently. Every time you cum on the dish the dish quality goes down. Apparently though all that matters is the level is high enough. Beware that you can only gift food once per day though.
-Sufficiently horny characters can invite you to have sex when you talk to them. This will give you stamina XP even if your balls are empty.
-Regular enemies typically only drop pale husks and scrap. To get more advanced components, you need to beat mutations. Enemy groups have a random chance to mutate on the first round. You can increase this by buying the 500.000 NUM item called Maggots and Bait.
-Warped Mirror Shards are pretty important once the NUM starts rolling high. You can use five of them to create an item that increases your level cap (you must use the item). Only bosses and mutations drop these.
-In order to craft higher quality items you need tools. You can get these from the tool merchant NPC (the one with the sparking bat). One of each is sufficient to craft practically everything at this point.
-I have no earthly idea how the endings are supposed to work.
-Silphium defense mobs scale with the MC's level. As a result, it's best to dedicate a whole playthrough to fight them by not selecting the option to keep MC levels when starting a new loop. Not sure how low that goes, though.
-Never sacrifice agility. It dictates turn order. Characters with too low agility never get turns. Conversely, if one of your characters is some kind of speed demon he or she will run circles several times around the enemies. (At 54K+ agility my MC usually has fifteen turns before anyone else's come up.)
-Your MC's skills and skill points get reset on every NG+. Only the first skill on the tree excludes the other two, and each one dictates which resources you get more drops out of. That said it usually also dictates your play style for that playthrough.
-USE EVERY ITEM AT YOUR DISPOSAL BEFORE THE FINAL BATTLE. That'll get wiped out once you reach the ending. Also make sure to equip your MC's equipment to someone else other than his weapon, that gets wiped out too.