Economy in Roguelikes - Part 2: Goals

Before I try to lay out what I hope for in Magecrawl's economy, laying out the main goals of what I'm trying to accomplish seems like a good idea. All game design decisions involve tradeoffs, and knowing what problems I really want to solve should highlight why I'm making certain decisions.

• Fun - This is a game afterall, not an economic simulation. If in the end, it doesn't make the game more fun and replayable, it is not work having.
• This is why some "optimal" behaviors, such as vacuuming floors clean of items, should be discouraged via game mechanics.
• Good risk vs reward curve - The game should reward players for risk, and not reward for "safe" grinding or farming.
• Prevent pudding farmings and other such nonsense.
• The rewards should be useful for any character type. It is not fun to traverse the dangers of a dungeon to find that the only useful equipment is not useful to you (Finding a +5 awesome sword when you are a unarmed monk for instance).
• Balanceable - There should never be one always optimal choice. Games are about tradeoffs, and clearly always better choices point toward brokenness. 
• Some systems make balancing easier or more difficult. Some games will be easier or harder due to the whims of the RNG, but on average things should make sense.
  
• Flavor - The system should fit in the existing world, style, and flavor. 
• Ease to implement - After all, I'm currently a one man team. 
• The most awesome system in the world would be great in theory, something I can implement "now" and improve later is better.