Sounds more like tea scale than mites. I have a similar, pernicious problem, and I spray neem oil alternated with sunspray oil (be sure to cover all leaf surfaces, top and bottom) several days apart in an attempt to keep them at bay. It's not an easy problem to solve, and I've read of people who cut their shrubs all the way down to rejuvenate them and eliminate the pest. I'm not brave enough to try that, yet!

I have no knowledge of this plant at all but let me just add that there is no weed killer/herbicide that can distinguish between a desirable plant you want to keep or one you want to be rid of!! They're just not that smart and don't work that way :-)) Manual removal is your best option. The alternative is to selectively treat this weed individual plant by individual plant but you still run the risk of damaging wanted plants in the immediate area. In that dense a planting, it's almost impossible to avoid. If you are physically unable to address the problem personally, perhaps you could hire someone to clean out the area for you? Even an unexperienced kid could do the job with proper supervision.

It's ground ivy, sometimes called Creeping Charlie. Very common, and easily eradicated with the right weed killer. http://www.canr.msu.edu/resources/ground-ivy-control-for-home-lawns

That's why you don't do "dormant seeding". Someone came up with the idea of just throwing seed on the ground in the winter out of sheer laziness and called it "dormant seeding", so it sounds like a legit lawn care practice. It's not. Maybe on a pasture.