Hows your latency? -try using quartz (addon that shows, latency on cast bar and when that next spell should be casted)
Even with 200ms you kinda need to notice the latency.
Using Starfall/Treants on each CD all the time?
Cant say much from this info. I would believe that try out get Quartz and spam the spells. If its still quite alot behind, well hopefully somebody that has more experience on Moonkins answers.