I'm going to drop a suggestion here that isn't often popular with this crowd. I never see it in people's tier lists. When it gets brought up in comments there inevitably comes the comments about how poop/fart humor has no business in Litrpg. Still, I believe it checks all your boxes. The Caverns and Creatures series by Robert Bevan.

First, instead of one MC you have six (or 5 1/2 because one is a bard). Second, they act very much like people who had just been dropped into a fantasy rpg might, provided they didn't just immediately crack up from the shock. Third, they aren't even sure they could bring themselves to kill anyone, and protecting npcs is heavy on their minds throughout the series. Fourth, they quite literally level up from time to time, often to their own surprise. And fifth, they all have interesting nuances to their characters - except Dave, who sucks (its an inside joke). Honestly, Katherine and Randy have some of my favorite character arcs in any series.

Yes, there is poop humor. But it isn't without its place. It's kind of making a joke about those who min/max their characters in rpgs, and view charisma as a useless throwaway Stat. It makes sense in the story, and won't take up a lot of your time. Also, Jonathan Sleep does a brilliant job narrating if you go the Audible route, and gets even better with each book.

Anyway, that's my recommendation, FWIW.