Regarding the small "fluffy" bits, this must have been caused by a somewhat blunt mill bit. Grabbed out a few other plates and they were all fine. Some had it in very small amounts. Apparantly I had just grabbed one from the box that just happened to be somewhat bad.
Here's a pic of another one - much cleaner as you can all see.
Regarding the chamfering, that's all just done by hand alignment on a drill press. It's quicker and cheaper than doing a CNC tool change. Can do by hand about 5 plates in the same time as the CNC can do one. Given that it is a hidden section of the block this is an acceptable compromise, or would people all be happier paying $1 more for a CNC to get it perfect when being perfect in this instance isn't important?