Do we have to link all the accounts listed on that page? For example, I've got PS4, Battlenet, and steam accounts. I do not plan to ever play on Xbox and I don't even remember what my Xbox live account is (haven't played since Xbox 360 and have never played destiny on it). I did play Halo 3 on it, but I never made a bungie account; my bungie account has only existed since destiny came out. Do I need to figure out what my Xbox login is or can I just skip linking that account? Sorry for the long question
Oh no, you aren't required to Cross Save all possible accounts - but we do require that, if you have accounts Linked together on Bungie.net, they all must participate.
In your situation, you can leave XBox unlinked and you can continue the process just Cross Saving PSN and PC!