Here, several years before he runs for the U.S.House of Representatives in New Hampshire, Stillson is a young travelling salesman hawking Bibles to midwest country folk.
Same thing with Stillson, only backwards: I wanted him to be authentically nasty and really scare the reader, not just because Stillson is always boiling with potential violence but because he is so goddam persuasive.
I also pointed out what might have been a little less obvious—it was important to establish, right up front, that Gregory Ammas Stillson was an extremely dangerous man, and very good at camouflage.
I wrote back to these folks, pointing out the usual things: (a) Greg Stillson wasn't real; (b) the dog wasn't real; (c) I myself had never in my life put the boot to one of my pets, or anyone else's.