First i would replace the sponges and chamois with microfibre- wash mitts and drying towel. With a sponge you are moving (and scratching) the dirt over the paint and a chamois is doing the same - with its flat surface it has to come across one tiny particle and the chamois drags (and scratch) it over the paint. With microfibre you lift it up into the fabric of the wash-mitt or towel.
I use the Microfiber Madness Incredimitt and Incredipad and thick soft Carpro drying towels.
But i realy think you should try rinse-less washing, it is perfect and safe for light dirty cars plus more safe than the washing method you do now. Rinseless: You use 1 bucket with about 2 gallon water with the rinse-less wash shampoo and a 2nd bucket with clean water to rinse the wash-mitt between cleaning parts of the car. Also make a mix water/rinse-less shampoo in a spray bottle for pre-wash on more dirty parts. Soak the wash-mitt in the shampoo bucket and gently wash a part of the car (not the whole roof at once, but smaller areas at a time). Dry that part with a soft, clean and slightly damp microfiber - rinse your wash-mitt in the clean water bucket (use your fingers through the fibers) and soak it in the shampoo bucket for the next part.
You can't wash the whole car first and then dry afterwards, it goes in parts. And you might think it takes forever, but a rinse-less wash cost you actually less time than a regular one.
For rinse-less wash you need a wash-mitt (or pad) with longer fibers (Microfiber Maddness Incredi- (-mitt, -sponge, -pad), Gtechniq WM2 Microfibre Wash Mitt or Chenille Microfiber), a few soft quality microfiber towels and special rinse-less wash shampoo (Wolf's Chemicals - Wash & Wipe Shampoo - Mean Green cleans very good, is wax safe, and with 1:500 is very economical).
You can't use regular car shampoo for this method and also a rinse-less wash is different from a waterless wash.
As for the scratches, i don't think washing scratches goes as far as onto the primer, then they would be very deep. Can you make a photo (with led light) to show?
Below you see a photo i took (iphone) of our daughters black VW Polo with washing scratches/swirls. Most German cars have hard paint. They look white but are just scratches in the top clear coat. These kind of scratches can be removed with a DA polishing machine.