casually imagines all them living under the same roof and having shenanigans…!

IKR?

I think the plot will be that after graduation, Hakuba gets a detective agency as his own and hires Conan to come by after school from time to time to help out with cases… being his sort of mentor, I guess. My HC is that Hakuba and Sonoko are very good friends already, so she’ll be by often… and Hakuba used to date Akako, but she broke his heart (and enjoys pestering him)…  and then subplot with Haibara and Conan, where she is documenting his answers to questions for prosperity “just in case he dies." 

Mogi just likes to borrow Hakuba’s car/money, and Souda is his partner.

It’ll be like a sitcom. LOL.