Where are these coins from? It's interesting to note that by the 2nd c. beards had gone out of favour with most of the Jews, especially the fashionable ones. See the paintings at Dura Europas synagogue.
A lot of time had passed since Christ and fashions changed. Growing up in the conservative Galilee in a fairly observant background, Christ would definitely have had a beard.
Umm, Armenia was actualy Christian long before Ethiopia I think.
And if someone was black, a colour that was unusual in the area at the time, you can be sure the Scriptures would note it. Have a look at Acts 8:27, for example.
The verses with the hair are in a spiritual context, white being the colour of purity and righteousness.