Painting advise for King Tiger camouflage

I think most of your questions can be answered by saying it's really personal preference. I think your air brush can handle the job with ease. I normally paint those patterns free hand and have no experience using the masks you speak of. I use Model Master paints, mostly because they perform well and are available at my local hobby shop. I haven't tried Vallejo model air, but I do use Vallejo model color designed for brush painting and they are outstanding. Realism is often open to opinion as well. I generally paint soft edge camo unless my references show the vehicle in question painted with a hard edge scheme. That's my two cents, for what it's worth.

You can use free hand or if you want hard edges you can try silly putty.  I know it sound wierd but it works really good.  I would roll small snakes to get the dark yellow.  I would start with that color as a base. Then apply the small snakes to cover the yellow that you want.  Then I would go with the dark red and then make larger snakes to cover the red that you want and then paint the green.  Also the silly putty will conform to the contours and doesn't let any bleed under.  Another thing it doesn't pull up any parts.  If you would like to see my example of this technique is my King Tiger in the First Big Cats GB.

I use Gunze and love them.  Bad thing about them is you might have to buy a couple of different colars to find the one that you want to use.  Also having to order them might be a problem at times.

I use a Pasche two stage brush, but I think your Badger will work.

Kim