mich,
short of a true handicapping system, this is probably the best alternative I have heard. I don't see an issue with the tiers or equipment model as it stands. This would be a great idea to allow someone to see one average for credit based matches, and another average for all other matches - a very quick determination could be made about the integrity of the player before accepting or denying a challenge match.
I don't know how mpc's are handled right now, but there should be no reason players of different tiers can't play a mpc match for credits with each using their respective tiers, equipment, and tee's etc. Course condition should be the same for each, and equipment and tees should be dictated by the players tier.
Again, great suggestion - very quick and easy way to determine a players integrity, and when sandbaggers can no longer find easy prey, it will help to stop the habits......