A:AnswerYes, this is normal. Some TV shows and movies may be bordered by black bars, often called wings or letterbox. These black bars are due to the aspect ratio the TV show or movie was filmed in - if you're seeing them, it means the title was filmed in an aspect ratio that isn't a perfect fit for your screen.
A:AnswerYour U-verse remote will probably still be able to control the volume (my Comcast remote does). BUT... you're still going to need two remotes. One Fire Stick controller for the Fire TV (which it comes with) and the U-verse controller for the cable box. Don't worry, you will get used to it. It's really not a big deal.
A:AnswerThe Manual is available under the Overview section.
Also, here is the link for the User Guide
https://files.bbystatic.com/w4LeoifjUPb2bumM9KS6CA%3D%3D/User%2BGuide