Short update on this:
Twitter
The credentials I have been provided for the @OfficialNuBits and @BC_Exchange no longer work. I have logged a ticket with Twitter on how best to proceed to regain access again.
Facebook
Also the credentials for the NuShares Facebook account no longer work. Will follow up on this later, not an immediate priority. Once I have the Twitter, I will try Facebook. Might make it a bit easier.
I don’t believe there was ever a BCExchange Facebook account.
Reddit
I have been successfully been able to login the NuBits moderator account for r/NuBits. That is good. So be careful what you post there 
Still need to look into the r/BCExchange account.
BitcoinTalk
I have obtained access to an somewhat obsolete account called NuProject which was used to advertise for developers. Not very useful, but will keep it in the collection.
Gmail/Youtube
Also been unsuccessful on this one. It should provide access to Google+ which isn’t used often and Youtube, but I’m not aware of any posted videos. Will park this one for now.
Github
I now have access to the Github account for the BCexchange.org website. So if there are any changes I have the ability to approve proposed changes. Will only do by motion or in case of obvious updates of links e.g. for new client.
Still need to dive into access for info@nubits.com email address and BCExchange bitcointalk user.
Please let me know if you are aware of any other social media accounts Nu or B&C used to have.