Bread – How much gluten should I add to maida flour for bread, and how

I wouldn't replace milk powder with vital wheat gluten. Vital wheat gluten changes the gluten content of your recipe. It's good for, say, turning whole wheat flour with a lower gluten content or AP flour into flour suitable for bread.

When I add vital wheat gluten, I subtract flour as your friend does. I only use it when I am not using a high protein flour.

The dried nonfat milk powder is likely in the recipe for flavor. I would instead use milk in place of water and either up the flour as needed or replace with flour as needed (you can tell this during kneading). I've done this just fine in bread recipes before.

I have been making a gluten free yogurt bread with the brown rice flour and haven't had any problems. You are going to need xanthan gum with any kind of gluten free mix you need.

With the other gluten free bread recipes I have in my book, they are all calling for a tsp of vinegar in addition to the dry yeast. Not sure if that helps with the rising, but my recipes have all come out exactly like the book says and haven't had a problem with them not rising. I just turn my stand mixer on HIGH and don't worry about kneading the bread.