Tucker is the same way with cats. Hence why Sebastian (stray we found and I was trying to adopt out) had to live in the dog kennel. I admit, I never bothered to train Tucker not to chase Sebastian because we had no intention of keeping the cat. Just wanted you to know that you weren't alone in haivng a dog that likes cats too much.
As for pulling on the leash, would you believe that Ein is the one that we have problems with? Yes, the littlest baby. All 30 pounds of him. That boy is more stubborn than any other creature I've ever met. We tried everything with him. He hated hated hated the halti, and flopped around like a fish out of water. But I made him wear it anyways. And he stopped pulling, but only because he was too busy sulking. Then I lost the halti. While on vacation in Gatlinburg, we went to Walmart to try and find something to keep him from pulling because when he had a "choke chain" on, it sounded like we were choking the poor boy to death (which we weren't, but strangers didn't know that). At Walmart, I found something like a halti, but that puts pressure on the chest/underarm area to prevent pulling. It works really well for Ein.