iOS submission and beta review process

I'm currently developing an iOS application for a client. My concern is the submission review process to the store, among other testing related concerns. I have submitted another app to the store very recently, being a very simple task manager app it was accepted rather quickly and didn't require any additional processing. Scouring Apple's documentation I can't seem to get a good idea of following: If I want to update an existing application on the store do I have to go through the review process again in full? If I have my app approved for beta testing release through testflight, is this taken into consideration when submitting the app for review to the store? If I want to test a new build through testflight, do I need to go through the beta review process again in full? If an app is approved on the app store, does it automatically pass the beta review? (This sounds counterintuitive considering you don't want to do a beta test after releasing to the store but in a scenario where you may want to do a closed release of an update for testing while a live version is up on the store) These are rather general questions which I thought would better serve as a resource for others reading this post than if I got too specific towards my own issues. I'm hoping some experienced developers of this community could offer some insight.