Don't fret.
People who object to Cesar's methods generally object to more forceful tactics he uses. Everybody agrees on setting clear boundries for dogs. If you want to watch a trainer who is much less controversial, try "It's Me or the Dog" with Victoria Stilwell.
Does Motley know any commands, like Sit? I would say this is the first step. This is easy to do, especially if he learned potty training so quickly. Or try Down. Next, implement "Nothing In Life Is Free". Before you feed him, tell him to Sit. He does not get his food until he does. Before he goes on a walk, he Sits. Before you play with him, he Sits. Before you rub his belly, he Sits. Teach him that you have ALL the resources, and that the way to get those resources is to obey you.
If you feed him at the table, stop. Ignore any barking or whining. Again, you are giving him information that these tactics don't work anymore.
On walks, teach him to Heel. If you are 100% consistent, he should get it reasonably quickly. If he pulls, stop. Don't start until he turns around and checks out what's going on. Commit to do this with TOTAL consistency for 30 minutes at a time (walk around the block so you are not stymied by traffic lights). Be prepared to outlast him, no matter how long it takes.
With aggression - obviously you need to err on the side of caution if he is biting. Don't give him the opportunity to bite anyone who is not ready to forgive him immediately. If you have someone who is willing to tolerate it, practice sitting with him on the couch. Have this very patient person slowly approach you. If he shows any aggression, say NO, and put him on timeout until he calms down. If he is able to tolerate the approach, praise him profusely and give him lots of treats. The Very Patient Person can give him treats too.
Post if you have any more specific situations you are worried about, and we can try to help you out. Good luck!