The earnings are in the form of Steem Power, Steem,and steem dollars. The latter was apparently an attempt to make a stable currency, which tracked the dollar, which failed to live up to its goals.

Steem power is very illiquid and takes time to "power down" the steem power into steem. Steem is the main currency, which you trade on the markets (along with Steem dollars).

Yes, although about 50% of the payout amount in the default case is in the form of Steem Power, which takes ~12 weeks to convert to STEEM which can be instantly traded like any other coin.

Delay aside, it’s all the author’s.