Nozzle scraping the print is classic over-extrusion. That needs to be dialled in 100%. The quality of your walls is indicative of incorrect calibration. If your calipers are untrustworthy buy new calipers. Otherwise you're just wasting your time.

Filament has a diameter of 1.9mm? Poor quality filament imo. I have seen this before and it is impossible to calibrate as it is 1.9mmin one place then 1.6 in another. With a decent set of calipers measure a 2 metre length at 10cm interviews and see how much it varies.

Retraction: set retract distance to about 4mm and the speed to say 30mm. To short a distance will cause blobs/artifacts and stringing.