I'm ashamed to say I wasn't acquainted with E.O Blauen's work before reading your post, Thompsonandthomson, so many thanks for directing me towards it. I found quite a lot of examples of his strips online, including this Lambiek entry: http://lambiek.net/artists/p/plauen_eo.htm
(which includes the chess strip you mention) and also this Wikipedia article: http://en.wikipedia.org/wiki/Erich_Ohser
A brave man and a sad end.
I don't know if Hergé was directly influenced by Blauen, or indeed if Blauen was influenced by Hergé. I don't recall anything I've read about Hergé mentioning Blauen, but that's not to say there isn't one (Hergé certainly borrowed ideas and elements from all sorts of sources), nor that such a link isn't covered in some of the many French-language books about Hergé that I've never read.
But maybe the similarities arise from both cartoonists being influenced by the same sort of silent comedy films that Hagen mentions. I wonder if the gags you mention - trick cigarettes, explosive chess players, jammed hats - can be traced to any particular old film routines both men might have seen.
Or, of course maybe both were simply imagining similar jokes from things from real life. Trick cigarettes would have been a common joke-shop item back then, and we've all known adult who take it badly when they lose at board games. (You should see my mother-in-law when she loses at Scrabble!)
Anyway, I shall continue to check out more of Bauen/Ohser's work. Thanks again.