But what do you call the copper coins ? like .001 gold?
We actaully call it .0001 gold. :P
And skinning/herbalism is fine. So is skinning/mining and mining/herbalism (this is probably the worst just b/c you can't have both radars up at once).
It's common to see a character with 2 gathering skills early in the game and then once you reach the middling levels, drop one of them to pick up a crafting profession.
This creates the problem that the ingredients you'll need for your basic recipes in your new profession will be the ingredients you sold off for money. Which means either buying them back from the AH or wasting a ton of time in newbie areas harvesting low level items.
As long as you don't care about "making items", two harvesting professions will work fine. Find some friends you can trade ingredients to in exchange for finished items.