I highly recommend reading the official dev blog. All your questions are answered there:
If you are a player that wants to play SSF, the Circler of Fortune is definitely the only option.
But Circle of Fortune does not automatically mean you have to do SSF.
Regarding selling items, there are several restrictions in place. Short answer: You can only trade things in the Merchant Guild that have no faction tag. Items gain a faction tag when they are accquired through any of the factions mechanics.
