I use a chain link dog kennel 10x10 6 ft tall my birds can fly in 1 hop to a roost I put in that's 5ft off the ground, I would find a pole saw and trim any dead branches and if you don't use netting I would have at least chicken wire on the top or 2x4 welded wire, the thing is chickens are the lowest on the food chain so even if you don't think anything will come around at night don't be fooled they will attract predators, I just bought a game camera for night time monitoring. You have a great setup and to make it very secure is the most important thing.