About that profile picture. The first thing I look at is the elbow and am still looking at it.
For an avatar, I would use
...in that image, you look unique and different from the typical avatar generally seen and would re-size nicely and contrast well..
As for which ones to get rid of:
That image looks very distorted and appears to me, to make your expression distorted and strained.
You have a great image there and see if you could get the edit that does not have your forehead cropped out...looks painful to the eyes, as I am admiring your skin and then suddenly...GONE!!!
Your other work is generally good. I would just pay care with the cropping, especially where your head ends at the very edge of the photo. It's a hard call to make (where to crop) but think of the overall composition of the photo and how you will compliment it.