Generally, I say the idea seems fine. I might suggest using a 16 bit value for the density - give higher resolution, but that may not be a big deal. But to me, the biggest issue on this would be to have a nice gui interface on the client for this. While using the text entries is also nice (so it can be bound to keys), getting a pop up or the like with the different object types and current values for it could be nice. Also, while you don't directly address the point, I think legacy usage of the old form should continue to be supported (ie, pickup 4 or the like) - a lot of people may have various keys bound to certain things (or just know things out of habit). You may also want a default value - ie, I may want value 15 for everything but weapons and armor, which I want something different. So some easy form to support that would also be nice.