The brown leaves could possibly be winter injury, but they could also be a sign of a root problem. Only time will tell on that one, and there is nothing you can do about either one of them. The circular holes are caused by shot hole fungus. Fungal diseases like this are very impractical to treat as fungicides would have to be applied minimally weekly through out the entire growing season. Avoid overhead watering and be sure to clean up any fallen leaves to help cut down on the spores that can spread. As far as what is eating the edges, we can tell its a chewing insect of some kind, but we cant tell you much more than that unfortunately. If the damage becomes much more extreme, call us at the Fayette County Extension Office at (859) 257-5582 to discuss potential resolutions.