Magic Ring was the original idea. I saw this erotic game witch hunt coming a long way and decided to make it play like LSH and add quests as ghost hunting was gonna be part of Magic Ring.
It's not a 4 in 1 game. There will be jobs players can do to pay for housing and other expenses. Ghost hunting is part of that and as a result LSHRM is integrated into Magic Ring. Recruits will be a thing but you will need to find meet each one of them and ask to be your assistants. Even Aoi.
Yeah, all quests will remain same unless they contradict with the plot. As far as I know, all the ones I've made so far are doing according to the plot.