Oscar's progress

Well I've officially had Oscar about a month. I cannot begin to explain how fantastic this little dog is. I am a very lucky dog owner!
Let's recap:
When I first got him I tested out all the basic commands and got absolutely no indication of any understanding. Not a flick of an ear or a thought directed towards me. Even small changes in my voice led to little response from him unless it was very harsh or very excited. He would crawl into my lap at any chance and slept the majority of the first week. Vet cleared him health wise just said he as a very exhausted terrier. Approx. 1-2 years.
He pulled at the leash a lot and scratched at the door. Lots of jumping and play-biting. Some playful snaps at the face, which was quickly reprimanded.
He throws himself around and generally ends up in a twisty pretzel while I'm attempting to snap his leash on. He flails and submits and wiggles and thrashes instead of standing on his two feet. Also likes to lay down at the bottom of the stairs and give the sad eyes.

A month later:
Commands:
Come is 100% at home. 90% at the dog park. We're still working on come while in the middle of dog play time. I usually can get him to at a minimum look at me, but actually overcoming the excitement of playtime is still a work in progress.
Down: Unless food is involved there is usually a stare-down involved. But generally if I wait it out for about 5-10 seconds he flops down quickly.
I've slacked of extremely too much in sit and stay, but he's done well in the little we've worked with it.
We had a week long stint of dumpster diving (aka getting into my trashcan and spreading it all over the apartment) but I caught him in the act twice and I very firm no and mean looks seem to have stopped that behavior.
Stopping the jumping/scratching/flailing at the door is a major work in progress, but I'm doing a couple fake-outs a day and today he sat almost long enough for me to snap the leash on and got HUGE pats for that.
He has a big dog bone that seems to have helped limit his enjoyment of dragging my clothes all over the house.
95% of the time on the leash he doesn't pull. Still working on this around other dogs and going down the stairs, but he's figuring out pulling means we just stand still or move backwards and that's definitely not what he wants.
Overall he's been super easy. Another 5 minutes a day actively training and I'm certain I'd have an exceptionally trained dog. But I'm lazy and I'm pretty happy with adequately trained dog.