I agree with the basic premise of this thread: in order to move more money around in the economy, some consumption is necessary, and that /fix and /smelt prevent consumption. /fix prevents consumption of valuable commodities (diamond, lapis, enchanted books, fully-enchanted items, etc), but all /smelt does is prevent consumption of fuels. So, that one is an easy fix: can we just make it so that you have to have sufficient fuel in your inventory to do /smelt? Then we can keep the perk and still help the economy flow.
/fix is a really valuable perk that is a major reason many people donate up to Elite, but maybe if you set a limit on how many times /fix can be used on a particular item, it would still help restore some flow to the economy.