I mean thats what to be expected?Slave route dont have any character development and mostly focus on lust and control.MC only using them to fuck and thats all it is.Master slave relationship,they dont love MC and only serve him.As for love route,it make sense MC interact with them first until they fall in love with him,thats the purpose.As for Kya,she might be creepy and old.But MC is the one make her starting to like men.Which also will be a new path for her soon.She will slowly explore her sexuality,open up with MC and finally love him like the others.Who knows,she might be one of the girls that will knocked up later.