Don't think I invented this theory, more a mix of the few things I've seen people talk about, but personally I believe that Mrs. L is a succubus(based on the list of fetishes on this page and a couple random Reddit posts) and the person she talks to in certain scenes is an angel or something, someone who opposes Mrs. L's goals(which I'll explain in a sec). As for who that is, I believe it's the Janitor, someone I actually missed seeing in my playthrough lol but I know exists from the outdated wiki and a couple comments here.
I think that "the Oculus" is overseeing a kind of bet that the succubus and the angel (taking the roles of Mrs. L and the Janitor, people who were quite different in the original version of the MC's life) made. Maybe whether the MC can turn his life around and get some action, become a better person in spite of his life and all the crazy changes going on(eg. with Lindsey).
I do wonder, who and how was this world created and why does it differ so much from the "original version", especially with stuff like Isabelle's existence, Jacklyn's role in the, Flora's attraction, and Lindsey's [SPOILER]. I don't know why the bet was made either, or why the Oculus oversees it and the extent of their impartiality---if they were the one who made it, then why is the world seemingly in favor of the succubus/Mrs. L?
Wish more people knew about this game and that I could talk about it to people without being outed as a gooner, I really enjoy the story :P