there are good and bad points: good is that you can play on the go, you don't need to find a computer, but the screen is smaller, harder to read, click on things
exactly, if somebody buys all of the things, it might change the price of the items, and there has to be some way how to control supply and demand in the game.
I think the reason why most of forums are dying out is because you can get most answers on Reddit, Quora or just ask your friends on Facebook. So there's less need to talk to strangers.