Well, like I said, humor doesn't have to clash with a serious, believable premise.
But if you want it to be canon, then that you can't really have a comedy series who has in its main characters are Vader and the Emperor.
I never said that was what I wanted. I have no idea why you'd think I did. I said it might be interesting to see a comedy series set in some hitherto-unexplored sidebar of the SW universe, or dealing with some of the comic-relief canonical characters in side adventures, perhaps like the old Droids series that Paul Dini wrote for, which was about some of the adventures that C3PO and R2D2 had during the years prior to A New Hope. Something that broadens the universe and reveals new facets of it the way The Clone Wars does, but in a lighter vein.
...and that's kind of the relevant distinction of a 'canon' Star Wars comedy. To be 'canon', it would need to fit. You could do a Star Wars comedy about Dexter's Diner or the Mos Eisely Cantina and make it like Cheers In Space. A TV show about a Rebel Hospital Ship that's basically MASH? Whatever. Many Star Wars characters could easily be used in such a comedy - Han Solo, naturally, could be trusted for a few zingers.
And yes, that's exactly the sort of thing I'm talking about (although not so derivative). Not a show about Hitler and Goebbels's wacky adventures, but (to continue the metaphor) something more like Hogan's Heroes or McHale's Navy -- or, for British viewers, Dad's Army or 'Allo, 'Allo! Something focusing on funny characters and situations happening off to the side of the main events.
Heck, I bet you could get a pretty funny series out of the misadventures of Han and Chewie prior to ANH.