How do i create complicated content type? My apologies for bad english.

I want to create educational website with user generated content. Sort of like wikipedia. The problem is content is a little bit complicated.
It must have 4 tabs, which represent 4 stages of learning. Each individual tab must have guide (a basic content page with a text), a f.a.q. page, and a forum for users to open topics related to subject of learning and current stage.
I draw a markup for better undearstanding:


I tried to make it myself by creating a content type with a Field Group module and ended up with this:


Current problems are: a) guide on each tab is just a text but needs to be a title, which leads to page with a guide; b) have comments instead of forum under the tabs and no idea how to make it.

I would absolutely appreciate any help.
Install Field Collection 


  Provides a field-collection field, to which any number of fields can
  be attached.
  
  A field collection is internally represented as an entity, which is
  embedded in the host entity. Thus, if desired field collections may be
  viewed and edited separately too.


and Field Collection Tab formatter 


  Field collection tabs provides a field formatter that allows you to
  output a multi value field collection field as a tabset, with one tab
  per field collection item.
  
  You can optionally choose a field from the field collection item to be
  used as the tab title.


modules.

Your common elements, guide, faq, forum goes into the field collection. Also put the stage title as a field in the field collection. Then use the stage title field as the title for the tabs.