Strictly for work orders only. Deams and Justin most likely added those as a catch all in case blizzard added those at a later date and/or in preparation to have them available for us in buying from the vendor like you asked about. For now though he only does work orders. Checking those other boxes will not do anything as far as i can tell. EDIT: Coming back I see I may have missed your point slightly. I am not sure if the bot can even buy from the trader of the day as I have only turned on the ores and herbs which has always been enough to keep me from running our of work orders. I doubt I will ever use those other boxes as if the bot did buy from the wrong trader of the day you could end up losing resources in that conversion. lol sorry not much help there.