Welcome and lets hope you are her forever home. I have a crazy chocolate lab at home. She is a handful at times but I find it is very very common with the chocolates for some reason.
Sounds like your off to the right start as she seems to somewhat understand. I have found that mine gets LAB brain. You need to find a way to first of all catch her in the act of of counter surfing or set her up. When she jumps up I would say "hey" really loud in a firm voice or some folks say a growl. Either should work to distract her from what she is doing. Its like you almost have to startle her for her to be distracted from the counter. If she responds to that praise her "good girl" and repeat
. My vet actually did this when I took Sophie in for a check up because she was jumping up on the counters looking for treats. She knows she gets treats at the vet ...they are so smart.
As for the chewing be sure nothing is wrong with her teeth. If you catch her chewing a show or something give her a No or thats bad and give her a toy she can chew on. So in other words your saying hey thats mine you chew your own stuff.
The thing is with a new dog you have to be observing them all the time. I would suggest she doesnt get the freedom to be able to chew. Until she can be trusted if that makes sense.
Both my dogs were tied to me for a while when I first got them. It was advised by a trainer. This way they dont have the freedom to go and pee where they want when no one is looking or chew something they shouldnt.
At least until they understand the rules you have.
Try to exercise her and tire her out...they always say a tired dog is a happy dog...
She sounds like a pup that needs some stability in her life and someone who is committed and can bond with her.
You should be very happy you listed some AWESOME qualities in her that are sometimes problems people post about here...
Would love to see a pic of her...
Come back and let us know how things are going. I am sure others can give you some great advice as well...
Cindy