So I've been trying this for a while now as well, even made notes of when Kevin appears to not waste time on certain days. I have all of the locations you mentioned and done all blunt answers along with the fixing car and the prank thing. I have yet to unlock his route... the only thing I see in your post that I don't know about is the "comfort room". Would you mind telling me where that is because I swore I went through this map and never found such a room. Unless I have it under a different name in my notes, also my notes only go up to day 18 since that's when the first scene should start but I never unlocked it so I always restart.