Help: Can i trade TF2 keys i bought from the market as non-premium?

I don't think one can trade items away as nonpremium, at least on TF2.

if you make a purchase on the store your account will automatically be premium?

I'm pretty sure if you're non-premium and buy any TF2 goods from the community market, they become locked to your account until used (as in consumed), gift wrapped, or the account becomes premium.

I don't see why not. TF2 premium mean dropped items are tradeable, to use market requires having billing address on file. I can give tradeable items to a non-premium account and they are still tradeable and marketable.

I saw some guys trading keys without having TF2 in their library, so I think the answer is yes (not 100% sure though).

thanks for all your answers :)