On the old prydwen.net, anyone who was a member of any guild or alliance would automatically be part of hib secrets. Even then you could apply directly for hib secrets forum if you were unguilded. Now, everyone just needs to use usercp and apply directly.
You do still need to get a person to confirm you (Banana/Penlid or Aran). I am not sure what kind of rule they have for non-level 50's though.
No the hibernian secrets forum access thread requires two members of the guild concerned to obtain access for the new user
Which thread is that ? Anyway, it is mistaken, anyone can see hib secrets once they are confirmed.