Bit of info on the pets:

Rufus: 6 month old neutered male Alaskan Husky (no idea what mix), 65lbs. Had from 8 weeks.
Steve: 5 year old neutered male cat, 16lbs. Had from 7 weeks.
Lucy: 12 year old neutered female cat, 6lbs. Rescued last year from abandonment.

Now when Rufus chases the cats I am trying to determine whether he is actually being agressive or just trying to make them play. Steve seems to accept Rufus for the most part and even rubs up against him sometimes. However Rufus does 'bat' him with his mammoth paws and when he chases seems to lunge bite for the neck, however Steve has never squealed so I would assume he has not been hurt.

Lucy is another matter, being much more skittish. Rufus seems to take delight in going after her and unfortunately she runs like crazy.

Generally Rufus is a good natured dog, spends most his time down the dog park just licking other dogs to death. He has also started some bad habits with us like biting the lead and our hands. When we try to correct him he lunges and growls as if to bite but if he actually connects he doesn't actually bite down.

Any suggestions gratefully received at this point. We want to stop all this stuff before he gets much older. He has also just started obedience school and also seems to have developed a bad habit or gnawing at his sides, which we have yet to determine the cause of.