Yes it counts as an RBI.
Yes, if a batter is walked with the bases loaded the batter is credited with an RBI.
No it doesn't count as an at bat.
No a walk does not count as a hit nor does it count as an at bat.
Yes they due. If it were any other hit, only the winning run or runs count.
No it doesn't count as a walk it counts as a hit by pitch or HBP.
Yes, the batter that walks in a run due to the bases being loaded will receive credit for a RBI.
It still counts as a plate appearance, and as a result of your plate appearance (bases loaded walk), a run scored. Therefore you are credited with an RBI. A sacrifice fly doesn't count as an at-bat either, but RBIs are credited. Double-plays are counted as at-bats but they disqualify RBIs. "At-bats" have absolutely nothing to do with RBIs.
the batter is out and the run doesn't count
No, walks and hit by pitch does not figure in to total bases.
if he gets a strike he is out. and after 4 balls you walk
No, a walk is a walk
If there are fewer than two outs, yes. If there are two outs, both the runner on third and the batter must touch their respective bases for the run to count.