if you purchase a medal from trade/auction does that automatically give you a gold account for how ever many months the medal is?

No. The Medal will be transferred into your inventory and from there you have to click on it. You'll see a list of things such as 'Put in in Shop', 'Put it in Vault' ,etc., etc. Along with one of those is a function that either says 'Use' or 'Activate' click it and you'll have a Gold Account for the X amount of months that it is designed to give.

cool! thanks!