I think the Shannon NSFW account adds a little more to the picture of who Shannon is. Why create a new FB account? If you look, JB also has two different accounts. From this information, I would deduce that the new FB profile using her professional name was created to support her acting/comedian career. The first mentions JB far more than the second account, and the same goes for JB's new FB account. I'm not really sure what that means, but it might be worthwhile to look into.
In regards to the marriage, for me, I think her ok cupid profile closes the case on that one. She lists herself as in an 'open marriage'. I have alot of friends who are in open marriages/open relationships and it is not uncommon for them to not physically see their partners for a short period of time but remain in contact through phone/email/text...etc. If Shannon's relationship was indeed ending, wouldn't she list herself as 'single' in her ok cupid profile? I know that to hertronormatitive friends/family an open marriage/relationship can look 'messy'. I think that they were perfectly happy, because if you think about it, JB probably had the same privileges as Shannon (being with other partners) and if we look hard enough I'm guessing you will find a similar ok cupid profile for JB if one exists. I think we are looking at two people who were in a loving, caring, but perhaps not perfect open relationship. I think that she and JB may have seemed 'estranged', and perhaps there were speculation/here say that they were going through a divorce but all the online evidence supports an open marriage that was very much still a marriage.
So, my off the cuff guess is that based on the fact that she is a very attractive young lady who has a large social media/internet/public presence I think we should look into if she had anyone who was harassing her online. If she was met with foul play, it is most likely because of someone she has met/talked too/knows from previous contact.
Hope that I am adding something to the conversation, and I hope we can figure out where we should be looking next.