historian’s separate fact from myth and they don’t always get it right remember both Troy and Pompei where widely considered not to exist till they where found by archaeologists. How does this affect things in TAU

The exact location of the original Stanley Pines Memorial Library becomes lost for a few centuries. Rather, there’s whatever incarnation is currently around, but not only has the forest grown, the town boundaries of Gravity Falls itself changes over time. Buildings collapse, papers burn, servers crash.

(Dipper is there for the archaeological dig they do when the site is eventually rediscovered. One of the diggers finds an old Barbie doll missing an arm and with half it’s hair cut off, and Dipper holds it in his hands, and remembers when three small redheads decided to have a spa day with all of their dolls…

It disappears offsite and never makes it to the lab)

Stan still has some contacts left from his less than legal ventures right. do they ever make a connection between him an Don Pines and if so how do they react.

By the time the Crew starts going, Stan is old. Like, really old. He is only with everyone for about another ten years before passing on- point being, if Stan is old, so are most of his contacts at this point. Anyone who would have potentially done Hank harm in the past is at this point content to let sleeping dogs lie.

Especially after they heard what had happened a few years earlier. 

Guys. Guys. I misread/interpreted something for a moment on this blog and was struck by the most wonderful idea/prompt:

Demonoligist Mizar.

Sometime after Mabel, another Mizar is reincarnated. She grows up, sees some freaky (normal freaky, not demon freaky) stuff and decides for one reason or another to go into demonology. She winds up meeting Alcor for the first time when she summons the dork (either on purpose, or he interrupts a more threatening demon) for her thesis project in front of the whole class, and he launches himself at her in a flying-tackle hug.

which once they get over the sheer terror is hella embarrassing. I mean, it kills the bad ass demon summoner cred she was going for.

So, I was wondering if this universe had an afterlife, I mean I know about the whole reincarnation thing, but I’m sure some souls choose not to, and if so is there somewhere they could go, or would they just die? Also, if so, what if Mizar or someone else precious to Alcor decided not to return, would Alcor ever try to visit them or convince them to return, or has he read too many legends and myths where someone tries to go there and everything end up terribly for them?

There’s not a strict…afterlife, really, but there is a place where souls can go between incarnations. It’s closed off to any being not purely a soul, which means it’s inaccessible to Alcor. If a soul decided to stay in that other realm for any amount of time, he’d be unable to do anything about it. If Mizar did it, he would probably spiral a bit–even if he shouldn’t depend so much on her existence, he does it anyways.

In terms of length of stay in that other place, it varies. Souls typically don’t stay forever; some souls bounce back for a short while and then get out to go live life again, some souls take a bit longer, others take ages, and then maybe there are souls that stick around to only occasionally live. 

How often do you think Dipper would make a reference that no one gets and then instead of just explaining it, he actually shows them the original work? (translated, if they’re speaking a different language by that point in history)

He certainly tries, but even translated, some things don’t age well. Especially fantasy things.
(Also, Dipper has to end up translating the things himself, and a lot of the language ends up archaic or clunky because languages never translate directly all the time).