Lower Layers are messy
Referring to the scratching, this could indicate that the nozzle is a little too close to the bed. This can be caused by a non-uniform bed, but that is unlikely in your case as you have tried printing on different areas of the build plate, this implies that the bed is correctly levelled. Still, the nozzle may be too close while having a perfect level bed (easily checked by using a metal ruler on its side over the bed). You could print an adjustable Z endstop trigger mechanism, there can be a few found on Thingiverse, e.g. this one or this one, it should enable you to fine-tune the nozzle to bed distance by turning the adjustment screw; the following image shows an example:



Note that a recent question has a solution that describes that the rollers had too much play on the profile.