Anon136,
The free market must be allowed to flourish on the blockchain. Why insist on settling trade in NXT for every transaction when every transaction already has a NXT cost to process? What if a consumer wants to use the Nxt AE, has NXT for transaction fees and wants to buy $10 million of oil from a reputable Nxt AE Issuer (vetted with history, positive transactions, other due diligence items).
In your scenario the buyer must buy $10 million worth of NXT (about 250 million NXT) or about 1/4 of the existing TOTAL supply of NXT.
This simple attempt to purchase 25% of the supply of the TOTAL STAKE of a cryptocurrency would drive the price of NXT far past reasonable and the order could not be filled at the preferred price (the price before $10 million of NXT buy orders hit the market, attempting to take control of 25% of the supply of a Proof of Stake Currency.)
Then the user of the NXT AE (now seller of NXT) would have to sell $10 million of NXT to buy $10 million of oil from the reputable Nxt AE Issuer.
Big money needs room to move. Nxt needs to provide that room to move. I believe my illustration showing why Nxt AE needs to allow trading between any pair is complete.
Keep in mind this is also one reason that big companies aren't going to start accepting Bitcoin soon, Amazon does 4.9 billion dollars in sales, now people would have to start buying Bitcoin's, Amazon would accept them, and use Bitpay to dump them back onto the market.. maybe there would be an equilibrium but I actually think that the price would start going down.. 9 times out of 10 people aren't going to buy Nxt just to use them to purchase an item at Amazon but if you buy something at Amazon, they'll dump Nxt onto the market. So unless people refill their wallets for everything spend, the price will actually start going down.
Us Nxt as a platform to facilitate transactions in a currency better suited to grow or keep a more stable value, and the price stays fairly even. I actually have an idea in mind for a perfect currency to run on top of Nxt that would be more stable and more trusted by both sides to retain it's value.
Nxt still maintains it's value and it's valuable because you buy Nxt to run services that require the forgers be fed. Anytime a transaction goes through, you have to at least own enough Nxt to feed the forgers, so you have to own Nxt, say everyone buy $50 worth, enough to send a NxtTxt, you could still hold onto Nxt and at time of purchase convert it to the currency running on top of Nxt to be held by the party on the other end, you need to pay in Nxt anytime you use a Nxt smart contract.
And you do still make sure that Nxt can be used for purchases.