Soin essence, the economic implication of Forks is not necessarily dependent on traditional mathematics/economics models because of the unpredictable nature of human valuation of a product?
Continuing with the unpredictable fashion of the human factor, I imagined a scenario where a fork happens in coin AB and after the split, and coin B is formed. People with Coin B can as well decide to pump in more funds to Coin B becasue the new coin aligns with views and has cut out out aspects of coin AB that they didn't like. Does this capture the idea?
I don't want to say they can't be mathematically modeled (in a purely theoretical sense they can), but it should be apparent by now that it's very hard to do well. I wrote a post on this particular issue a while back: https://steemit.com/writing/@blocktrades/alice-has-5-ice-cubes-bob-takes-3-how-many-ice-cubes-does-alice-have-left-for-her-afternoon-thai-iced-tea
On your second point, sure. Any change in rules can potentially cause the coin users to place more value in the coin, even removal of rules they don't like.
That means a fork that leads to division isn't necessarily a bad thing. Prior to reading this, I thought it's occurrence is generally a sign or indication of the end of a project.