I'm not sure this system will hold up in the long term if simple transactions are going to get fees beyond a reasonable amount.

f you are receiving tiny amounts (e.g., as small payments from a mining pool) then fees when sending will be higher than if your activity follows a more normal consumer or business transaction pattern. As of bitcoin 0.5.3 the required fee it will ask for will not be higher that 0.05 BTC, though for most users there is usually no required fee at all and 0.0005 is the most common when one is required.