Few questions about 4.4, maybe issues?

[gaiusjaugustus]

I finally upgraded from 4.2.10 to 4.4. Wow, things are so beautiful and sparkly!

I have a few concerns, and at this point can't tell if I did something wrong or what.

1. I noticed that I should be able to edit the navigation menu. However, when I add an entry to the menu, it's nowhere to be found. I did make sure that I should be able to see it when I'm logged in.
   
2. On the Homepage as well as the messages page and the My Account, there's still the old theming. Is that supposed to be that way? The dropdowns for the Settings menu doesn't work on that page (or the messages page).
   
3. Any tutorials yet for building our own plugin?  I see the demo, but not sure where to start?  I'm having to rewrite a lot of my custom functionality to upgrade to PHP 7 and the thought of building a plugin is enticing.
   

Thanks in advance for your help, and thanks for all the hard work everyone put into making US awesome!