That’s great that you are making note of where the root notes are, though whether playing them once or twice when moving up and down the scale is really just a matter of preference. The same goes for breathing out into the harmonica. You’ll find it’s a matter of sound and preference. I think it sounds great, especially in solo playing, or with an acoustic guitar, and especially when it is used in a rhythmic way.
It sounds like you are on the right track! 🙂