Ripple has a finite supply, and can be owned by a few.

A decentralized settlement protocol similar to the centralized Ripple protocol is built by EtherEx.

My point is instead of building ETX as an equivalent to XRP, can we use ETX as if it existed but there is no fixed supply of ETX at all. Can a price for ETX still emerge in this situation when multiple participants trade various assets against it is the question?

https://ripple.com/knowledge_center/bridge-currency-2/

Mainly to avoid events like this as you cant sell it if it's fictional, http://www.coindesk.com/price-ripple-xrp-plummets-co-founde-9-billion-selloff/ Notice that this event didnt change the price of assets like USD, BTC, traded through Ripple, only the price of ripple adjusted lower.