Isaiah 53:2 ESV For he grew up before him like a young plant, and like a root out of dry ground; he had no form or majesty that we should look at him, and no beauty that we should desire him.
KJV:
Isaiah 53:2 - For he shall grow up before him as a tender plant, and as a root out of a dry ground: he hath no form nor comeliness; and when we shall see him, [there is] no beauty that we should desire him.
As to the long hair........maybe, maybe not.........as I understand it, the custom for Jewish men at that time was to have their hair no longer than just above their shoulders. With the exceptions of the Nasserites who took a vow not to cut their hair. Jesus was a Nazarene though so don't know if He took that same vow.
As for grooming..........while the Bible doesn't give explicit detail on how Jesus or the Disciples groomed themselves, we shouldn't believe they didn't. It is also not recorded in Scripture where they went to the bathroom, but surely they did. And we know that for the greatest part of His ministry, there were women traveling with Him and the Disciples, and they could have very well tended to such details as cutting His and the Disciples hair.
He was not Arian.......blond hair, blue eyes....nor was He black......He was born of the lineage of David, a Jew. He was not of great stature, wildly handsome, or from a wealthy/powerful family.........for all of these would have detracted from His Gospel in that these would have given reason to some for believing in Him. That is not what He wanted.
Ok, my thoughts............as we are speculating here anyway........