I always burn in a new load a bit before closing the bypass, but when I load I am usually down to coals and the cat isn't active. Even if the cat is still hot, you might want to burn in the load a bit to remove some of the initial moisture from the wood. If your cat is still hot and your wood releases moisture, it may thermal-shock the cat and cause it to crack (ceramic.) The cat will still work if it's cracked, though.
Definitely check the cap and clean if needed. Even though dust was being pulled up, draft could still be seriously reduced. Not sure how you are gonna get to it. Maybe you can tap on it with a pole to knock the creo off?
A couple more questions: Where does the prevailing wind come from, the other side of the roof ridge? If so, it's possible you could be getting a downdraft when the wind blows hard from the other side of the roof.
Also, what is supporting the chimney? It looks like it is leaning, and that the portion coming out of the house is slanting downward. Could just be the camera angle though. Usually, there is a bracket fastened to the house which supports the weight of the chimney from below...
And lastly, is that a radio antenna?
Everyone is pulling for you to get it all working right, good luck!