I love the Hireling system, I look forward to the letter each day as it adds background story to the game. What they need is a bit more interaction. We should have to pay them for any mats they deliver to us, after all that is what they are doing it for. We should also have the ability to ask them to focus on certain mats we need and of course special orders should come with a higher cost.
It sure would be cool to actually meet them from time to time in game as well.
Any other ideas?