If I win a game that gives me an extra copy - can i give it away here?

I created same thread in the past. See
http://www.steamgifts.com/discussion/iu61F/a-game-i-won-comes-with-free-copy-can-i-give-that-away

As for your second question, it should be fine unless there are specific countries listed. Otherwise it'd look like this.

its ok to give it away since u actually used the steamkey. it doesnt count is regifting.
for the restricted gift just google: in which region is ( 1 of the countrys name thats restricted )?
basically u well get the answer faster

what both SaraphL and Murtida said...

They should be as restricted as Gifts you buy in store - if your gifts never had restrictions, those ones also won't have them.