when asked by ace or the young doc who is sold the pipe,where he comes from,Mr.Gaunt tells him the plains of blaine

When Alan Pangborn blasts Leland Gaunt with the joke flowers near the end he mentions "The White".

When Alan uses the paper flower trick on Leland Gaunt the light from his hand is like that of the talisman and he thinks "The white! The coming of the white!"

When Sheriff Alan Pangborn does the magic trick that creates the bouquet of paper flowers in Leland Gaunt's face. Instead of flowers he gets 'a blazing bouquet of light' and feels a jolt of power run up his arm. He thinks 'The white! The coming of the white!'

Sherriff Alan gets a little help at the end of this story from "the White" in defeating the evil store owner.

the 10 o'clock people is about the vampires from the tower books

Dees works for Inside View

Its possible that the titular neighborhood 'Crouch End' is a Thinny, or simply a thin space between our world and 'Todash.' Granted, it has more of a Lovecraft feel about it, but the vague horrors described are also similar to the nameless horrors that inhabit the Todash Space

This is a Number 19 connection...In the short story, Sometimes They Come Back, in the collection Night Shift, the car that the thugs drove in was a 1954 Ford sedan. Add the year 1954 up and it's #19

Lots of connections, Reverend Flagg in credits, supernatural abilities from other Stephen King novels affect Havens towns people, Thinnies the gate way to interdimensional time space travel are present in Haven. Names of some other towns are from other King novels. And probably more if I read all of Kings works! Super fans would pick out connections faster I am sure.