I mean that no-one will be able to simple put a bunch of iron on the network and amass a fortune. The only way they will receive a "large" number of ?coins is by selling something or trading for them.
Again, mining is still "viable," it's just not a primary driver of the market in any critical capacity, including the "early adopter" syndrome.
Without even a basic explanation of why a 'bunch of iron' (or even virtual iron) can't simulate trading under your system and therefore game your 'activity indicators' - this doesn't sound well thought out.
What is going to verify that it's real economic activity?
A central review agency? An AI you just need someone to code up for you? A voting system of network participants? (For which you'd also need to provide mechanisms against gaming)
How is a transaction which didn't involve delivery of a good or service going to look different to the network than one that did?
How can the network know whether the 2 ends of the transaction are even genuinely distinct entities?