problems with barking.

My parents have a yellow lab and they keep a "choke collar" on her for walks.  They sound in humane but the muscles on dogs necks are so strong that they barely feel anything but tension with those collars.  It has helped Pfeiffer considerably to have a choke collar on to walk.
 
That's my suggestion.  As for the barking, I can't help!  Sorry! 

You can place the collar all the way to the top of the neck, that way she wont pull as hard and cant help herself with the shoulders, second is redirecting her attention to you, there is a lot of different techinques for that, for the barking you can une body blocking, you can stand up between herself (really close) and the cause of the barking and make a noise so she understands you dont like what she is doing

Find a behaviorist that can help you with that since only reading about it wont take you to the highest level of success

Or you can actually teach loose-leash walking rather than just masking the problem by making it painful to pull.
 
If it wasn't painful, it wouldn't make them stop pulling, they'd just pull more. And some dogs who are highly pain-resistant, this is exaclty what happens. It doesn't hurt them, so they keep on pulling, eventually damaging their tracheas.

We had the pulling problem with our lab/greyhound mix, even with a choke chain.  The Humane Society suggested a muzzle harness, and it has literally worked a miracle.  They told us that because the muscles in a dog's head aren't nearly as strong as the muscles in their neck and shoulders, they can't pull on a muzzle leash like they can a regular one.  Our dog is now easily controlled and much better behaved on walks.

We have 5 dogs and they all walk perfectly on a leash.  Put on your running shoes and get a rope a little longer than your usual leash.  Did you ever do the shuttle run back in school?  Go ahead and do this with your dog.  Run, stop short, and run the other way.  Be ready for a jerk because your dog probably won't be turning with you.  Dont turn slow to give your dog time to think, just stop short and take off again.  No, your dog won't like it too much, but the dog will learn that they have to watch you if they don't want to get pulled around.  Ideally, you want the dog to stay next to your left leg, they should watch your leg to know when to move, when to stop, and when to turn.  Say the word heel why you are doing this and they will put 2 and 2 together.  Finally, when you stop, tell her to sit.  All of the dogs that I work with will usually sit on their own and focus both eyes on you when you stop running.
 
Your dog is assuming the "leader role".  Instead, you want your dog to look to you for guidance.  You have a great mix, labs and heelers are both highly intelligent.  A lot of working breeds do need a job to be happy, we have one working dog that points squirrels in the front pasture on her time off!  She just has to have a job.  When you teach her how to heel, you are giving her a job, you are giving her something to focus on.  If her focus is on you, then she will look to you before making her next move.  She will also associate a tug of the leash with heeling.  That way, when she does pull towards something, you can give her a tug and she should return to your side and return her focus to you.  This will not happen overnight, so be patient and work with her a lot at home before venturing out.  Praise her when she is good, plus the lack of tension on the leash will be her own reward.