"Exactly. The REAL reason they don’t want members to celebrate Christmas and other holidays is to keep them away from non-Witness relatives and friends." Spot on ! Once your find out how wonderful your "worldly" family and friends are, your J.W "conditional" family and friends are just not of an acceptable standard.
I don't know for sure, but it was, I think, the desire to make the Bible Students stand out somewhat that Russell used the name Jehovah so much, and certainly it was big part for the choice of name for the group that Rutherford made.