(i) At exchanges.

(ii) Let me know when you find out (some would say just hoard it, but if everyone did, Bitcoin would eventually atrophy).

(iii) Fundamentally, yes. Bitcoin fulfills the three defining criteria of a fiat currency - storage of value, unit of accounting and medium of trade. Ergo, Bitcoin trading is conceptually similar to forex. However, Bitcoin operates under a completely different environment compared to fiat currencies; chiefly, it is a decentralized, peer-to-peer cryptocurrency that is not subject to central banks interest rates, balance of trade, national debt and political stability. The learning curve is shallow, but intrinsically distinct to fiats.