A) what grounds could it be DF (remerber he only voice his concern
to his wife)?
Yes, his wife can turn him in for anything whatsoever.
B) If he is DF, when the letter is read about is DF, what will they
announce. (conduct unbefitting A Christian)?
My understanding is that they currently say, in their announcement, that so-an-so is no longer a Jehovah's Witness.
C) The letter that is sent too HQ, what reason will be given
for his DF?
What BluesBrother said: Apostacy.
D) Can one be DF for doubt?
BluesBrother: However, I have read plenty of experiences on here about people who only raised the point with elders in response to their questions, but judged guilty of Apostasy.
I was disfelowshipped simply for questioning something without spreading it around. I did speak to an elder about my concerns. My appeal committee quoted a scripture about creating sects. When I told them that I had done no such thing they responded by saying: "You are a sect of one".
Villabolo