I know the slut class allows more submissive roles but I found another class called mare and I don't understand what it does for "hiro" and does it add any roles? Also are there other classes?

How did you got the "Slut" class, and what does it does exactly?

You can get the "Prostitute" class if you get enough levels of Lady of the Night, tho I don't know for sure what it does.

The "Mare" class is from dealing with centaurs, and I think it lets you join their camp without getting the bad end.

You can also get the "Queen" class from the Beastmistress Drow... but it's a bad end.

And I think there's a "Gobbo fuck-toy" class as a bad end on the Patreon version, not really sure.