Perhaps one way to reduce the grind would be to make more use of the gifting mechanics. Gift someone a Dildo Set 9000 and bam: their corruption is up by four. Gift someone a watch or something and boom: they get two more trust. (So long as these are universal: all girls accept any item, then it could work well.)
Keep in mind that due to the construction of the game things have to past a threshold, they don't need to be one to one. So I believe I already noticed some of it happening, but it seems as though corruption/trust was increasing in gains as I progressed through a character's story. 5/6 ways through the main quest? Each event raised the corruption by 3, 4, not 1. (I believe it was with Carla/Missy that I noticed this.) Doing more of this would be good.
Unfortunately I do think that some of it is not removable. At a certain point it is very very lucrative to do things: the business eventually gives an enormous amount of money. If I need any for the entirety of the future of the game I am set. The problem was grinding the Cock & Bull until that was lucrative. (Though still fairly quick.)
Stats on a personal level (strength, intelligence, dom, endurance) are actually very easy to level and should require no adjustment. So that leaves money and girls' stats that need to be rebalanced... Somehow. It's the early portions for money that need a bit of rebalancing: so perhaps make working the Cock & Bull and getting more money not just reliant on working hard. Work there three weeks, and you pass the threshold for the next upgrade. Work nine and you reach another threshold. This is slow and probably poorly chosen numbers but just an example.
Another way would perhaps give something to the player that increases their gains. Go to the strange shop and obtain a mood ring: your trust now is levelled up by two instead of one each time you do a trust event. Some items like that could be effective to reducing the grind: if prioritized early game their utility/effect is very very large.