Not only are the Regulators another name that Ted uses for the Low-Men, I also believe that the "Sinister No-Face" from the Regualtors book is another apparition of the man in black,walter odim,marten broadcloak,randall flagg,ect...

Edward Paladin is obviously from another level of the Tower, where he is a twinner of Johnny Carson, host of the Tonight Show. Also, the currency he has is different, just as described by Pere Callahan in Wolves of the Calla.

The priest, Phil Drake, has startling similarities to Father Callahan. the biggest include his burnt right hand. Others include the fact that he was once a priest and he knows about the effects of drugs and alcohol. "A tall fellow of about sixty, with blue eyes and a nose that had been repeatedly punched in losing bouts with the bottle."

The man who was once a priest but is no longer one. In the first meeting I thought might be Callahan under a different name. He make a point of not wanting to be called "Father." The second time Bart meets him I am sure after this paragraph "Drake (the former priest) unfastened the rubber band, holding the bills with his left, manipulating with that oddly scarred right." Callahan has a scarred hand, he has left the church, and he refuses to be called father. The same a Drake in Roadwork. Stephen didn't even know or remember that he he was bringing a character from 'Salems Lot into this book. It's not highlighted as a connected book but it is. The Street Priest Drake is Don Callahan.

dearborn avenue, Roland used the name wll dearborn in wizard and glass

ok granted not a stephen king book, but it is a mini series that was penned by him. The points that i can make out with the dark tower are as follows, group of pychics go into a haunted house = Manni and the whispering cave although pyschics are not magicians to people in rolands time it would have been classed as a magic of the great old ones, the manni are mentioned as being able to open doors to where they do not know, so i drew the conclusion that where the pychics open the door to the afterlife it could be the same kind of way that the manni keep and hold the door open for rolands ka-tet

In "The Waste Lands", Co-Op City is mentioned.  Co-Op City is the city where "The Running Man" is set.