If I don't hear back from Tweak I'll throw out another post as well. Correct me if I'm wrong but so far I've extrapolated Varric probably knows of the Flame's reputation from his dealings with pirates, recognizes Temp's suit as Myrefall fashion being of vain nobility and spent some time around Thomas being on the VIP level of the ship as it were. Since they both fled from Glaifast we can build on that at some point. As long as it makes sense, feel free to make any such interpretations yourself, no character is created in a vacuum and the most interesting ones have ties beyond the Main Story.