JoeBlow, kindly acquaint yourself with the "multi-quote" button, it's the one next to "quote". That way, you don't need a separate post for every one-line response.
Once is not the most pleasant part of town, but from Corrientes and up, Pueyrredon is fine and certainly not dangerous. Jewish neighborhood, lots of synagogues and kosher restaurants.
Try Hotel Abasto, it's a fine hotel, and has good deals sometimes.