9.5 week old puppy regressing?

He is cute!  Are you sure he's a mix?  I only see lab in him.
 
Puppies change from day to day, so it may seem like a regression to you but it's really not.   Dog training is all about ups and downs and eventually he'll get older and you'll see more ups and downs.  If he's getting "aggressive" pick him up and put him in his crate with a chew toy or walk away from him - don't engage him and let it get to the skin breaking stage.  Puppy teeth are like razors at this age which I guess you've learned!
 
Regarding your question about being home all day with him, you should be careful about catering to him.  Puppies sleep A LOT - is it possible part of this "aggression" (I'm putting it in "" because I really don't think you are seeing true aggression) is an over-tired puppy?  They do get really bratty when they are tired.  Do you crate him for a couple of hours at a time in a quiet place so he can sleep? 
 
You're not ignorant at all and you show a lot of love and dedication by asking questions and really reading the answers.  Please do go to a puppy kindergarten class with him.  They have their pros and cons but a big pro is the socialization aspect.  Another is that you will learn a lot in the class, especially from watching other people interact with their dogs.  You won't learn that by having someone come to you for one on one training.
 
My first dog was a lab puppy that I got at about your age.  Boy did I have a lot to learn and it was tough in the beginning and I thought it was way more than I could handle and I felt like I knew nothing at all.  Then I signed up for an obedience class, then another, and I met other dog owners and starting going to a dog park, then I started agility, and then herding....and before I knew it that 1 puppy (bought one Sunday on a spur of the moment because he was the cheapest lab puppy in the Washington Post classifieds that day)opened up a whole new world for me.    He's gone now but having him really changed my life for the better - no matter how hard it seemed in the beginning.  So hang in there, it sounds like you're doing a great job just remember he's a puppy and don't expect too much from him.

Your pup is being completely normal.  He understands the limits from a few days ago, he's trying to test his limits.  And if you'll notice something else, puppies get really bratty when they get tired.  Be patient, be firm and be consistent.  Once you put limits in place, don't waver, not even "just this once."  Your pup will respect you for it.

agilebcs: We must be DC Metro neighbors!

agilebcs- I am sure he is a mix.  His ears are a dead give away (long Coonhound like ears).  Tough to see in the pics!
 
I appreciate the time you took to respond.  You are right, I am feeling like "what did I get myself into."  I understand puppies not tons of sleep, and believe me, I try to give him as much as he like's.  Thats when my wife and I get to be productive
 
xerxes-thanks again for another great post.  Its so hard to think what he is doing is normal, because it seems like all he wants to do is hurt us.  We are very consistent with everything we do, so there is no problem there.  I am going to stay the course and ensure my pup gets everything he needs, including fantastic owners.  It just gets frustrating when you can't even pet your puppy or play with him because of the extreme biting and growling.
 
Thanks again!
 

Two more pic's of the little devil[]