Millie Bobby Brown does an awesome job at playing the character Eleven. 
Yes, she is a fantastic actress. This break out role has made her into a A-list actress. The entire cast is cohesive and wonderful to watch.
It is so funny because Steve Harrington's character was supposed to be the biggest jerk character ever. However, the actor who played him is so charming, he became a central favorite character!
Yes, his character arch from antagonist to protagonist is a great addition to the show. The Duffer brothers thought that the actor had a likeable charisma and chose to change the course of his character.
Interesting! Stranger Things was definitely the best show of 2016. 
Yes, its debut was a huge hit. I am looking forward to the release of the 4th season. It should be sometime this year, but I do not know what month. Do you?
I do not. However, the Duffer brothers did mention that season 5 could be the end of the series. 
While I understand the need to neatly end and wrap up a series, I certainly wish it would continue on for more seasons! While there is certainly a demand for more seasons, maybe they are concerned about maintaining the integrity of the storyline.
True. I would rather them end it early when the show is still interesting than them waiting until the show isn't even enjoyable anymore.
Yes, unfortunately many great franchises have found themselves stretched thin as they force the storyline to include more seasons.