...sitting here, drinking a cup-a-Joe, for the most part things look acceptable,
but it also looks like there is a slight bit of under-cutting which could be
heat or wire or hand technique... I'd try bringing the wire speed up a little and
see if that gets you into the bacon.
I would start by removing the rust and making sure the metal is clean. You will see a difference for sure. Are you dragging the gun in a straight line? If so practice on making a C pattern remembering to stay on the front edge of the puddle.