Do I trade Marion Barber for Tony Romo?

No, This trade would take away a top 5 running back for a QB that is coming off injury. This would not be good for you seeing as there are many new good rookie QBs that can do good for your team. Matt Ryan, Trent Edwards, Tyler Thigpen has averaged 19fppg over his last three. The tallent pool at QB is quite flat but RB gets very Steep at the top i wouldn't take this trade you gain maybe 5 fppg over your current QB at most but loose a huge producer.