This follows a beginner tutorial by tutor4u. I thought I could get a clearer understanding how the NLA editor works because his tutorials are so well presented for beginners. Unfortunately, even though I was able to follow the tutorial easily enough, I’m more confused about the NLA editor than I was before I started the tutorial!! 
I didn’t see anything wrong with it. So what problems did you had with the NLA Editor?
Like I said, tutor4u Blender tutorials are very easy to follow. So I was able to follow the tutorial, and my animation came out like the one in the tutorial. But he does some steps with the NLA editor as well as the Graph Editor which, although I was able to copy what he did, I didn’t understand what I was doing or why.
There’s no point discussing what I didn’t understand in this forum, since this is for showing finished animations.