I have seen a few things floating around, but that outline sounds pretty good. If think something like that could be executed pretty well. The trick would be finding the right kind of characters to carry the film. Considering the mixed reactions to ATC we know it is not an easy feat. I like the idea of the new crew looking through Egon's notes. Something like that would really keep The Spirit of Egon so to speak in the film. Much the a same way they handle the absence of Miagi in Cobra Kai. I love the thought of the new crew trying to find Ray and when they find him having Ray and Winston be the Active mentors to the new team through the majority of the film. Having Peter showing up at the end to help save the day would be the icing on the cake.
I still have hope of seeing something like that someday. I am sure Bill Murray could suit up for one day of shooting a scene that doesn't have to be any longer than the cameo he shot in ATC.
We will have to wait and see.
Found it. Someone wrote it in end of 2014, I think that was before the new movie came out (I edited it for length, etc.)
GB3 starts out with no ghosts. The movie starts very matter of fact, mundane, like GB1 did.
Students of Columbia University (the same as in GB1) doing particle research in particle accelerators, have a groundbreaking experiment go wrong.
Suddenly impossible things start to occur but VERY SUBTLY. Like physical constants appearing to no longer be constant but starting to fluctuate. The Planck length (for whoever knows what that is) starting to become measurable, etc.
This touches one of the students (Oscar) on a personal level as deep down he has those experiences from GB1 hidden away. (It's the reason he got into the field, to try to rationalize what happened.)
In his class is also deceased Egon Spengler's daughter, who knows little about her father. Oscar and her meet in a funny way during one of the experiments. In trying to understand the strange experimental results at Columbia they decide to go through her father's old notes. She knew he was a theoretical physicist. Slowly they uncover the strange truth about her father. (And first time viewers who have never seen Ghostbusters get pulled in at this point.)
It starts when they are sitting at her house at night and hear this strange noise. They search the whole house trying to find the source of this strange noise. Until finally, in the dusty basement she opens a drawer and the noise is heard loudly and we see a PKE meter lying there, wings fully extended beeping like crazy. Neither of them know what it is.
They also find a dirty crumpled piece of paper with a name and an address. It says:
In the dusty archives of notes they find information for a warehouse safe housing the old GB equipment.
They try to find this crazy eccentric old man.
Things keep trying to prevent them from finding him. Inverse serendipity? Like random chance isn't random anymore. In very subtle but interesting ways.
They meet Winston along the way, who now lives in a run down ghetto and (because of his Ghostbusters past) has become completely fearless. Not just kind of brave but actually 100% fearless. It leads to funny scenes with a completely fearless old guy in a ghetto.
The situation is getting worse by this stage.
What's also funny is contrasting how modern kids, i.e. Oscar and Egon's daughter, approach things completely differently to these old 80's dudes. The whole political correctness angle, social media, etc. could be used to offer funny interactions between the new and old team.
In the end the torch is passed. Venkman shows up and ends up accidentally saving everyone and then they work together to save the world.