I can help with the sitting part, maybe.
A dog will often sit, when it wants something and can't get it on it's own...like the demonstration of the difference between wolf and dog--->
They put a piece of meat tied to a rope, the other end to a stick...the meat in a cage, the stick outside. The wolf is intelligent enough to grab the stick and pull the meat towards it, but it can't get it through the cage...however, the difference in the evolution of the ancestor wolf and domesticated dog is that the wolf will not turn to the humans (trained wolf, humans present) for help, it will keep on keeping on.
The dog, however, will try to get the meat the same way, but after a short while, give up and look to the humans for help, and sit down in the process. Dogs sit, for many reasons, but one of them is that they are unsure of what to do next.
I used this to teach my dog to sit for just about everything, and I rarely have to say the word. After a while he just began to do it. Wants to go outside and is standing up...I grab the door handle and he tries to push forward, but then I just stand right there and eventually he will sit. This progressed into an immediate sit position for anything he wants, and he does it all on his own, no words.
Now, the actual command for sit...I think is pretty retarded, so I try to use the silent version as often as possible. plus, I don't care if my dog is standing by my side or sitting by my side, if we're out and about and he is calm, he can stand all he wants.
The treats were what worked best to get my guy to sit, and from there I incorporated that into everything else (going outside, play time, etc).
Took around 2-3 weeks of fairly consistent efforts to get him to sit on his own with no commands for me. And this was simply just going through the motions of standing by the door if he had to go out and putting my hand on the handle. By the end of week 3, his butt was on the floor before I could even reach the handle.
Same with his Kong...he loves for me to put treats in it so he can roll it around and get them. He started by picking it up in his mouth and carrying it around, no particular course, just around, then he'd drop it and look at me. This was my cue from him that he wanted some yummies.
So, I took it a step further and I asked him to bring it to me. Of course he didn't the first many times, but I still did the same thing...I'd see him pick it up and carry it around, so I'd go into the kitchen and neal down with my hand out. Sure enough, after a few weeks, he actually stopped roaming about and brought it to me. Dropped it on my foot the first few times, which hurts...a lot, lol, but after that he made it to my hand. Now, I can ask him in plain english "You want some treats? Go get your Kong." And by the time I get to the kitchen, he is waiting there for me...I hold out my hand and he places his wobbler gently in it.
Now, getting him to bring me back the baseball outside when we play fetch...that's been another story. This knucklehead would rather play keep away and wants me to chase him. I've tried everything, no luck as of yet.
As for going potty in the house, just gotta be patient and definitely use treats outside after they go. Use lots of praise when they pee or poop and have a treat ready. She'll get it, just keep on. At that age, bathroom time is going to be every few hours.
As for recall. If my guy is in the back yard (fenced) he'll come if I just whistle or call his name. If he is in any type of excited state, that becomes 10 times harder.
I too had a lab mix and never had to do any type of formal training with him, he was just a bad ass awesome dog.