So I have a question concerning the special cards that come out as you play.
Some cards will say “play before your turn”
Does this mean that I would play the card, resolve it’s effect then leave it in front of me AND THEN proceed to my turn? (By either drawing or taking a fortress from the middle of the table, or attacking a fortress?
The “trade fortress” special card says that it can be played at any time during the turn. Does this mean that I could take a fortress from the middle putting defenders under it THEN play the card and trade fortresses with an opponent?
Yes, correct. This is a possible use of that special card.
Does playing a special card count as you taking a turn? Or do you play a special card and still have to draw a card or take over a fortress?
You play them additionally, so you always have to draw a card or take over fortress(es).