From what I understand there's no J in the hebrew language so I think the Most High's name originally is YHWH, Yahweh, YAH. Yahshua came in his Father's name and his name would imply that he would save his people from their sins (Matt.1:21). As I understand, it's YAH (Father's name) Shua (salvation). The English translation is Joshua so I see that as more appropriate than Jesus.
Still, I don't condemn or judge anyone for calling the Father Jah, or the Son Joshua or Jesus. God is above ignorance or translations of His name and He knows when we're sincere. For almost two thousand years people have been more or less ignorant about the true name and I'm sure people have had and still have an intimate spiritual relationship with the Father, Son and Spirit while using the name Jesus for example.
I'm not learned in this so I can of course be wrong in some of this but.. right now I see it as true so I try to practise it.
Some say it's Yeshua or Yahoshua. Anyway, these all seem more close to the original than Jesus.
Here's some further reading: http://en.wikipedia.org/wiki/Yahshua
Just an add about the Comforter which might have been obvious.
I'm positive that Selassie had real trust and faith in the Father and Son and had therefore received the Spirit. My humble opinion is that that is the reason why the works of the Comforter manifested through Selassie by the will of Yahweh.
If my opinon is true then there's a similar situation written of in one of the letters. I'm not calling you fleshy, I'm just expressing my thoughts on Selassie being "just" a vessel and not entitled to the honour belonging to the Most High and his Son.
 For ye are yet carnal: for whereas there is among you envying, and strife, and divisions, are ye not carnal, and walk as men?
 For while one saith, I am of Paul; and another, I am of Apollos; are ye not carnal?
 Who then is Paul, and who is Apollos, but ministers by whom ye believed, even as the Lord gave to every man?
 I have planted, Apollos watered; but God gave the increase.
 So then neither is he that planteth any thing, neither he that watereth; but God that giveth the increase.
 Now he that planteth and he that watereth are one: and every man shall receive his own reward according to his own labour.
 For we are labourers together with God: ye are God's husbandry, ye are God's building.
 According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. But let every man take heed how he buildeth thereupon.
 For other foundation can no man lay than that is laid, which is Jesus Christ.
 Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble;
 Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is.
 If any man's work abide which he hath built thereupon, he shall receive a reward.
 If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire.
 Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?
 Therefore let no man glory in men. For all things are yours;
 Whether Paul, or Apollos, or Cephas, or the world, or life, or death, or things present, or things to come; all are yours;
 And ye are Christ's; and Christ is God's.