You certainly can't be stupid! To have made that much improvement you must know enough!
I have got a long training line, I hate flexis as there is no control and they seem to teach the dog to pull!
He is fine if the other dog ingnores him, but my other dog is very friendly and wants to play all the time. When she is with a dog, he seems to need to proterct hre and rushes in barking. Sometimes he will almost join in the game and does his excited bark, but the other dog usually gets confused (understandably!) and won't play.
Re the DDA, I have been led to believe that it doesn't apply to dog/dog aggression. When Dan got attacked the 2nd time (same 2 staffs) I ranrgrr trherrr police as the 11 yera old children walking them actually set them on mine and Myrtle was only 6 months old at the time. The police said they couldn't do a lot as it was only dog on dog.