I know that you can't directly convert gold to silver using the Currency exchange, but I was wondering if you could "sell" gold on this site for silver, or buy past relics with it from other users. Are these things possible/allowed in Midorea?
Yes, this is definitely allowed, and people do it. You can open a shop in the Market forum and sell people gold there. In fact, a lot of people who can't buy it themselves would probably appreciate it.
Uni has swallowed me whole, in more ways than one, sorry guys. Feel free to PM any questions (or nonquestions {or anything else, no limits here}) you have, although I don't know when I'll get to them since I'm barely on atm.