Dogs are really good at reading our body language, they are also really good at taking advantage of our mistakes.
Labs love food so instead of you chasing HEr have HER come to you call her and have a treat as soon as she gets to you feed it to her. This is you teaching her to come as opposed to run.
Re chewing remove as many of the objects that she is NOT allowed to chew as possible, get yourself a kong and put some puppy biscuits in there, that will help take her mind from other chewing activities.
The idea is to set in good bahviour patterns that is so much easier than corrective training.