I think Othello, in theater history, has been played as everything from an Arab to an African - depending on who wanted to play him and their own interpretation. Edwin Booth played him as a prince out of the seraglio while Paul Robson, obviously, played him as an African. And you’re right, many references to black and sooty skin within the play.
I like that sometimes in the opera, the singer will black his face but leave his neck and arms white!
In any case, Shakespeare went to some pains to make Othello obviously different and foreign to the Venetians in the play. I have no problem with Othello being played as an Arabic type, but he would need to dress in a different fashion than the Venetians and should be at least a little swarthy so as to match the descriptions of "blackness" in the play.
His foreignness and perhaps, overt masculinity make him appear as a heroic figure to Desdemona and other Venetians, and his blackness makes him an unacceptable son-in-law to Brabantio.