Plus it seems odd to me that an Empire like the one in the Elder Scrolls is able to so well maintain a single centralized currency, as well as prevent it from be melted down or counterfeited.
In response to this and your first post, this is what I have to say.
This is based on historical precedent on this planet, take it as you may when applying it to Tamriel.
The septim is not a measure of currency like the dollar is, but rather it is a gold coin of a set weight. Let's say a septim weighs 1 point. See where I am going with this. The english monetary unit is the pound, that's because once upon a time this was a coin that was 1 pound of silver (I think it was silver anyway) You see all over the place balances. That's because when you buy something, you don't count out your coins, you weigh them out (like the stories of crooked merchants putting their thumb on the balance so that the buyer would have to add more coins)
When basing a currency off of weight, counterfeit is impossible (they don't have the ability to give a fine coating of gold, and even if they did, that's the assayer's job to check) This also allows the currency to adapt over a very large and diverse economic landscape. It's like if we bought things with gold bars. An economy like the empire doesn't use money established by a federal bank or anything like that. They just have their coins minted as a sign of their power and wealth (if the coin has the empire's symbol on it, then obviously it really belongs to the empire) ala Mat 22:19-21 Show me the tribute money. And they brought unto him a penny.
And he saith unto them, Whose is this image and superscription?
They say unto him, Caesar's. Then saith he unto them, Render therefore unto Caesar the things which are Caesar's; and unto God the things that are God's.
Note, this is posted here ONLY to show that historically, if the emperor's image was on the coin than that meant he claimed that as his money, at least in theory. This is not an attempt to discuss religion as such is against forum rules.