Too many issues with Groups and SharePoint backing site

I'm testing out the new Groups with SharePoint backing site concept and the strange thing is that I see Files, Notebook, 'Shared with us' and 'Recycle bin' in the left side navigation but I don't see any pages. 

If I click on the cog at the top right then click Add Page I get a new interface for page creation that I haven't seen before (looks somewhat like Sway), but okay that's fine. I add a title and some text below it then click Publish. 

Issues: 

• Once I navigate away from the page it's gone, I have no way to get back to it. 
• I tried to add a Document section to the page but it won't take PDF, only Microsoft Office document extensions by the looks of it
  • I tried uploading a PDF, it uploaded then promptly disappeared. If I go back to files though, it's there, but you can't add it to a page.  
• When I click publish the page shows along with the content I added to it, but when I click on Files in the left side menu... nothing. There's no pages at all! 
• I click on the Cog at the top right of the screen and choose Site Contents... it just takes me back to the Files page. 
• I do the same again but choose site settings, same result
• The group site itself has been added at the root of /sites/ which means I have no control of the information archticture of my SharePoint Online instance because it should have been created as part of my /Customers/ site collection but I just didn't have that choice. 
• If I click on Conversations it launches me into a new tab redirecting me to Outlook online...? 
• I added a Yammer section to a page with a link to a particular external Yammer group I created for this group. The Yammer plugin/add-in shows with a login button which when I click it opens up a popup followed immediately by a dialog asking me to allow the browser to close the window. 
• I click on members, it jumpts out to Outlook?

This is a feature I was rather looking forward to, but I must say this is the single worst Office 365 user experience I've had so far.