I only ever burn tumblers and never have a problem with mushrooming/soot - I did have problems with jars mushrooming in the past though - how odd.
I believe yankee doodle are the UK wholesale importers and you'd have to contact them about a wholesale account (something rings a bell with the whole Kringle fiasco last year) - I reckon Q import theirs separately though.
Also - why no "A Child's Wish" or "Paradise Spice" in the TSV? They're also Q1 fragrances. I'm gutted that Golden Sands is US Exclusive and will be keeping an eye on yankee scents 4 u for it to come in stock.