As for the depth, I have found bluegill spawning in water as shallow as a couple of feet or less. If they are pressured from spawning cycling to spawning cycle, then they will move to deeper water to avoid spawning beds from being seen. This is especially true in small lakes where there is heavy fishing pressure. The 15-acre lake my son lives on is a prime example of what I am talking about. The bluegill in this lake always spawns in shallow water and always in the same area of the lake each year. They choose the same bedding areas in this lake each year because of less fishing pressure on the lake. The lake is there mostly for the beautiful scenery around the lake, and the walking trails next to the water's edge. In other words no one is interfering with the spawning process of the bluegill here but me and my son.
The bluegill was probably the first fish a small child landed while using live bait, such as a cricket or redworm. That is how I got interested in fishing years ago as a youngster fishing our small farm pond. The fish was easy to catch, even with cane poles and live bait. Once my dad taught me how to land the fish using a fly rod, there was no turning back, I was hooked for life, and will be until the day I retire from fly fishing, and I hope that is years from now. For me, landing a large bull bluegill or an average-sized bluegill on a lightweight fly rod is the ultimate in warm-water fly fishing!