We can all imagine what he would have looked like and it wouldn't matter. Jesus came to this Earth as an average appearing Middle Eastern Jew. The Jews were God's Chosen people. He would have all the characteristics of a Jew. I do believe a blue-eyed halo wearing blonde would have stood out in the crowds.
I think you’re likely safe on the “blue-eyed, blonde” statement; however, “average-looking” is a conclusion based on evidence not in hand.
If I had to guess, I would guess he was above average in looks and definitely charismatic.
;)