eMunie promise of keeping its value stable is not credible because they don't have the ability and means to do do. Since when people selling eMu en mass, they have to have a huge reserve of dollar to back the money up otherwise its price against dollar will have to fall. They won't be able to do that.
When people decide to sell eMunie on mass all creation of new coins stops right away. Also the foundation will be backed up by several million dollars to do some initial regulation to stabilize the price in the first weeks.
It has to be understood that in any market price has always been acting as a necessary signal to guide the behavior of the market participants. For example: with bitcoin market if you are holding 100 bitcoin, when the price of bitcoin raising you would be inclined to sell them to more willing buyer, but when the price falls by half, you may decide to keep them all since you evaluate that the potential of the bitcoin is higher than the bitcoin's price right now. All bitcoin market participants follow the same process using the current price as signal as if they are many ships and liners following the lighthouse to reach the shore The true price is discovered organically.
Now you don't have the price signal here so the price of eMunie is artificially kept up. This is going to be a mess
Of course you have the price signal. The fiat/emunie exchange is buildin into the system, and the system can react accordingly to stabilize the price while keeping up with demand.