Well erm not sure about the dead body...Test it and see...Otherwise just trigger it to break when player walks on it...Not the effect you're after but I don't know.
And my idea well:
Ok so you have 10 spawns for CT and 10 for T correct? Well place a box over each spawn and tie it to trigger_teleport. Then make sure they are all turned off. Now this bit you'll have to figure out but find an entity that can trigger things randomly and set it to trigger one of the 20 teleports at start of each round.
That way a random player will be teleported to your open area at the start of each round. Hope that helps.