Not much you can do with dappled light. You just pretend it is creative rim lighting.

These are beautiful, but, I still don't understand why you would get blurry photos with aperture priority. If you are shooting at a large aperture, you are going to have max shutter speed. Just pay attention to what the shutter speed is doing and bump the ISO accordingly.

I do not get blurry photos on aperture priority and that is shooting whippets running at 40mph or horses over fences. I just make sure that my ISO is high enough to keep things at 1/800th or faster. In bright sun, that is ofter ISO 100