They abandoned the loose leaf printing pretty quickly and reprinted everything as regular books.Thieves guild designers notes: The creators of the system and magazine talk about their intents for the system and plans for future products. Loose leaf books that you reassemble yourself? Another experiment that will pass into history unlamented. Another bit of interesting historical perspective here.
Not really a step toward focussed indie games. It was more like modules with thiefly adventures. Even though the party is in the thieves guild, they had the regular D&D classes. So there were wizard who steal and fighters who steal and clerics who steal, etc. The game started as just expansion rules for D&D but by the time of the second edition (which this issue of Dragon talks about) the game had turned into a D&D clone. I played it back in the 80s and own most of them.The dragon's augury: Thieves guild also gets reviewed here. Focussed around, well, the class that you would expect, and scenarios for them, it is both more and less complex than D&D in various ways. I suppose it might not be as focussed as some modern indie games, but it's certainly a step down that path.