Overall looks pretty solid to me. If you can repeat shots with regularity I'd say keep on going.
Having said that, (if I were your coach) I'd like to see a little more knee bend at release, which is an easy fix. When we have more knee flex it allows the large muscles such as the quads and hamstrings to carry the load, so to speak.
Conversely, the less our knee bends, the more pressure will end up on the front of the knee joint, and the lower back usually carries too much of the load. Perhaps a little bit of knee flex in your set-up will help you accomplish this more naturally.
Realize that "you should bowl like you" because your build, flexibility, and footwork will be uniquely yours, but letting the legs provide the "power" is easy, and then the arm is only needed for "direction". I really don't think an overhaul is the answer when a slight tune-up will do the trick. Good luck.