First, I'd like to gently suggest that you stick to one thread. Pick one and continue to post your questions to it, even if you have no responses in between. It will be easier for us to follow your story.
Going dark means limiting communication with your H as much as you can. It's a tool you use to remove yourself from the emotional ups and downs that inevitably follow contact with your H in the beginning. It allows you to step back, take a breath and regroup. It gives you space to learn what may be happening to your H, to collect your thoughts about how you want to proceed, and about what you need and want going forward. If you feel you need that space and time, consider going as dark as you can. Do not initiate contact with your H unless it's an emergency. Respond to his contact only if you must, and only about the most important things you still share -- finances and kids.
As to your second thread / question, I suggest you not worry about that now. Protect yourself in every way, work on yourself, read the resources, learn everything you can about what you are dealing with. If and when the time comes that you need the answers to those questions, you will be in a much better place to answer them for yourself.
M 65 H 64 T 39 & M 36 @ S 12/08 Two Ds
Do you know that the harder thing to do and the right thing to do are usually the same thing? Nothing that has meaning is easy. ~ The Weather Man