The work you are doing is absolutely TOP KNOTCH! Very nice work, my question is if these holes are going thru? If they are simply craters you are so close to PERFECTION it isn't funny. If that is the case, simply epoxy prime the area and what the epoxy doesn't fill fill with polyester putty. We are talking VERY minor stuff here, if they are simply a tiny pit.
If they are going thru, or if you simply want to move to another step in your journey to absolute perfection, well that is another story and you need to work on the welding using the tips the others have already told you.
If they are only a tiny pit you simply need to perfect your welding with the tips given. A little more of an overlap between welds may do it. I personally find that I weld much hotter then others to get this done. The first spots, keep the wire speed and heat down. Once those are done I turn up the heat and wire speed because I have the nice thick metal (the previous welds) to weld to and I want to be able to weld into those welds with a little more authority. But just practice with the tips given on some scrap. You are a cat hair away from doing flawless work, you have true talent and passion. And nothing can overcome like passion, nothing!
Cutting the wire off and purging the gas right before you weld is a good tip if you are looking for perfection. The gas is a "shielding" gas, it pushes away air borne contaminates. If you just do that then the nozzle is full of gas and when you hit the trigger it's right there for you. Cutting the wire, that is a very important step. The little ball of wire at the end is actually "oxidized" it is technically "rust"! You are pushing in a glob of rust when you weld, think about that!
But honestly, you are doing the kind of work that I would be thrilled to have every time. As a pro I have learned what I can get away with, you haven't.
Because of this you are doing the kind of near flawless work that I would often skip, and simply make up for the flaws with a little filler and get on with life. Why, because I know what I can get away with.
Many, MANY pros who do this every day wouldn't or couldn't even get close to the quality you did there.
Taking the time to do the beautiful work you are doing has eluded me often. I can't wait to get back to doing some restoration work (my own car) so I can have fun with it like you are. Doing regular old collision work every day you loose some of your passion, YOU have some passion that is for sure.
Let me make this perfectly clear, that work you are doing is absolutely BEAUTIFUL and you have NOTHING to even think about IF those are just little divots in the metal which I think they are from what I can see in the photos.