Do you know that feeling when you know exactly what is that you want to write (in this case, my character's background), but you just can't get the words to come out right and even though the idea sounds awesome in your head, it looks ridiculous in text and you rewrite it a billion times and it just gets more and more stupid-sounding?
I've got that problem right now.

Oh man, those religions. You don't even know. Writer's block is currently killing me there.

<Snipped quote by The Mad Hatter>

Oh man, those religions. You don't even know. Writer's block is currently killing me there.

I feel your pain, man. I did all that crap once, too. Then I decided never to make a "custom" fantasy universe again because there was just so damn much work with it - half of which I never thought of myself but other players were all "what about..." @.@

I've been thinking about currency, BTW. My first thought was going with the good ol' classic of "gold", "silver", "copper" and so on coins/pieces. If you make it coins, the size of each should be the same and such every coin would have the same value. Making one piece of gold worth approximately the same as a week's supply of food and so on (say, about 70$/65€ (that's just about what we use each week in a family of three (two adults and a toddler ... and a cat, a guinea pig, a bunny and 3+ axolotls))), it'd work out quite well, to me. Silver could be worth, like, half of gold (35$/32€), copper half of silver (17,5$/16€) and so on.
From there, you can obviously name the coins differently. Since I'm assuming that you want one type of international/global currency and not one for each nation, the name should likely be something like the name of the world; Oriast.
I did have one other idea, but I've forgotten what it was.