Wanted to be sure I'm reading this right. Accuracy allows a roll to apply damage/wounds to a model until it suffers a wound, correct? Meaning say a unit has 3 Defense, I roll 1 accuracy and a total of 3 hits all of those hits could be applied to model with accuracy assigned to it, then it takes the 1 wound and the accuracy goes away, right?

Yep.

You got it.

If it was any other way it would either be a little busted (able to take out multiwound models with 1 accuracy) or very lousy (1 accuracy for 1 Hit, basically making it 100% useless unless the target only has 1 armor to begin with)