Hi danny'sowner and welcome. One of the best things about this site is the search function. Enter the key words from your questions and you'll pull up lots of good discussions between dog owners with similar questions and a variety of good answers. My 2 cents, in order of your questions: Keep being patient with the chewing, you're almost through with the bulk of it. Continue to use kongs and rawhides, but don't let the dog swallow big pieces of rawhide as they may get stuck. Aggressiveness--probably not at that age, search "reactive" and read the descriptions and solutions. Choke chain--be sure to learn how to use it properly, consider a martingale chain and prong chain as alternatives. Your dog is an individual, and as you see posts by other owners about their dogs you'll recognize the similarities and learn the solutions. Good luck--and post some pics!
Liesl, b. 1/1/11