I would change a1 AF-C priority selection to "Focus". Your current setting allows the shutter to release even if focus has not been achieved.
Also, I'd be very surprised to find that matrix metering gives you proper exposure on your subject. I'd try spot metering although personally I prefer manual exposure based off incident light. This works best except in cases where lighting is constantly changing.
Keep shutter speeds at 1/800" or faster.
So some searching on "long lens technique" to get some ideas how handling can affect the quality of your pictures with these long focal lengths.