Actually if anyone wants the backstory on when and why actors at cons/shows started CHARGING for autographs, Jennifer put her finger RIGHT on the reason.  It was the example of the Sports stars -- and you can blame certain actors from Star Trek: Deep Space Nine for starting the trend with actors.

Reason I know this was that back then I worked a few weekends a year for what was then Creation Conventions, back when the events they put together were more like conventions than the arena sized shows with no fan contact with the talent which are now the ONLY thing most people know as "Star Trek Cons".  For many years actors did cons unpaid except for a per diem and travel expenses then they went to being paid, which turned their con appearances into speaking engagements for pay only, with very little interest in the fans.  Autographs were also done for no charge, even when a dealer would show up with a dozen or more that the actor KNEW they would sell for a profit.

Then , as I said, one or more (I forget the particulars and I'm not about to name names anyway) of the actors from the third Trek series, having had no experience with Fandom, considered the experience simply an engagment for pay and wanted parity with the sports stars charging for autographs.  So, Creation started charging for autographs, and photo ops.  Eventually even the old guard went along with it cause, frankly, if everyone else was being paid, and they hadn't seen a residual in years, they would have been fools not to take the money.

So, this is why the promoter run shows all charge for autographs and photo ops, and the ones like the Fest who don't are almost non existant these days.

Hall definitely had "creepy" down pat. The women on the show seemed genuinely apprehensive around him, which helped increase the tension factor. As most others have said, though, I don't believe he would ever have been able to bring the nuances of the character that John Karlen did. When I watched these episodes in the early 90s (which was the first time I saw them), I felt that the tension factor actually decreased noticeably when Karlen replaced Hall. The fact that John was so familiar -- and I knew what was going to happen with him when Barnabas appeared -- the base effect was Willie Loomis changing from an authentic threat to an old friend having a bad day. In the end it worked out for the better, but I really did relish the tangible sense of menace that Hall conveyed. At that time, he was the one human character who outshone the supernatural in terms of sheer dread. Though his acting was merely adequate, in concert with the accomplished actors around him -- particularly Nancy and Alexandra -- his scenes stand out as being very dark and fear-invoking.