Don't give up on Scrappy yet
He's starting into puppy adolesence (his teenage years) and will be recalitrant, moody, disobedient, etc
I am a beleiver in 'positive re-enforcement' training over clicker --- you always have love and attention on you.
He needs to burn off Yorkie energy - so a long play session outside (not alone) each day will help alot. Also, consistency (especially at his age) will get him in line --- sit means sit not think about it or not do it. As 'no' means 'no' with consequences for not obeying - be it chewing barking, nipping, etc. Have him wear his collar and leash in the house and when he starts chewing/barking, etc tell him no and leash pop him (a hard tug on the leash so he turn toward you then praise and reward for stopping. As for the bathroom prob - crate train him. Cowboy (my 11 mo old ESS) is the first dog I have crate trained - and I will ALWAYS use one from now on. Our field trainer has lifted Cowboy off his feet (at 54 lbs) by the sides of his neck and yelled 'no' in his face - once a dog is off his feet he has no control - and by usung the skin on the sides of the neck you have control of the mouth (can't bite you).
Potty=reward (loves and treats) - make sure he has plenty of 'acceptable' chew toys...