I used to be a goalie so have had a good look at the goal several times. The following addresses the 2 issues raised:
Hand - Absolutely 100% went for it with the correct hand, the argument he should have gone for it with the other is complete nonsense, he'd have been much further away from the ball using that hand. It never even occurred to me at the time that anyone could suggest he should have used the other hand, having gone back and analysed it I still don't understand it. It's not correct, in fact it's completely incorrect, no grey area.
Positioning - I agree he needs to move one step to the right and anticipate where it's going, it's unlikely if he makes that step the ball can still beat him at his near post, so that step would have been the right one to make just before the ball was struck. It's not a horrendous error, in fact I wouldn't even really classify it as a mistake, more he could improve on his anticipation in order to have a better position. We are talking ONE step out though, he's not massively out of position or anything and it would take a great shot to beat him from that position.
If you look at Rose being completely done with the trickery you would say he sold himself completely and allowed a left footed player to cut back in on his left foot for a strike at goal. If you are to attribute blame to anyone it HAS to be Rose, there's no way he should have let him back on his left, he just gets completely done. Anything after that isn't comparable in terms of 'error'.