So, I did some of those updates in El Cap and it made it where I couldn't log in and things just got all jacked up. I tried installing Sierra and now my system is a brick. So, either the motherboard died on me or sierra bricked my ****. Just prior to the brick happening, my sierra install wouldn't work because of USB issues with the mouse and keyboard...ones that I never had with the El Cap Install.
So, my recommendation to you all: If you buy from the people I bought from, just use caution. El Capitan is just a better and easier install on this machine than Sierra. I highly suggest getting it to 10.11.6 and leaving it alone. I can only try and jam a square peg in a round hole so long before I go grab the round peg again.
Don't be afraid to ask a lot of questions in a lot of places until you get an answer.