Does Knights of the Hollow Hill ("other cards you control do not provide a gold bonus") cancel the effect of Burned and Pillaged? I'm thinking yes...
KOtHH + Burned and Pillaged?
It does not "cancel" the effect in a technical sense, but yes, if you attach Burned and Pillaged to a location controlled by a player who runs the KotHH agenda, the -1 gold is ignored.
how about if YOU are running KoTHH, and you attach it to the location of someone who isn't?
Burned and Pillaged doesn't provide a gold bonus by itself. The -1 gold and -1 initiative is text gained by the attached location. If the location is controlled by someone who doesn't run KotHH, it will provide the -1 gold and -1 initiative. If the location is controlled by someone who does run KotHH, it will provide only the -1 initiative.