Very interesting indeed.
I used to be a student of Linguistics (well, still am I suppose) and, whilst Ebonics is somewhat more of a dialect, it still holds up to the basic strictures you are trying to explain, so, well done!
Despite this linguistic background, however, I seldom thought about this sort of thing... I've used different langauges successfully in campaigns, but I've never really analysed what "Common" was. Damn my Anglocentric mind!
Thank you for writing such an article to get me thinking!
This is a really cool idea :)
My only suggestion would be to have written somewhere a riddle that tells the players to use their hands... I could see players floundering around for a while before they said anything like "I touch the painting", etc.
I wont lie, I've been meaning to join Strolen's for years, but, oddly enough, this NPC finally tipped me over to the side of Strolen's. I had to join to vote and comment on it!
I was wondering, however, if you'd mind me adapting it slightly for use in a supplement I am making for WFRP2e, about the Kislevite city of Praag... Basically, I would be adapting her name to be Karly Geltseig (which just means "Goldwin" in very loose German) and that after the events in your timeline, she was 'discovered' by a to-be lover, and since fled to Praag where she continues her trades.
I promise, if you allow me to use it, that I will include you in the credits and make sure it is attributed to you :)