I think if you made a bridge in the middle that is only player collides, it would be more interesting because of 2 reasons:
When flagger runs through middle, it can get killed and drops the flag to low route
When flagger runs throught low, it would be easier to kill him from middle
Also, i dont think anyone is going to go top or even the route between middle and top, because its very hard to get to them. Remove that bit sticking out in an flipped L shape to make it easier for people to go up. Other than that, the map has some nice potential.