I see several things here.
First, you are not using a finishing strategy for the walls of the pockets, hence the scalloping. Depending on the CAM tool there are different ways do this, but, as Vince said, you want to leave a little for the finish pass. It doesn’t appear you used a finishing type toolpath at all. On a Nomad with aluminum, I might leave 0.02 to 0.05mm (0.0008 to 0.002") for a fine finish pass.
I can’t tell from the picture what tool you were using, but I am guessing it is a flat (square) end tool for both the 3.2mm (0/125") and the 1.6mm (0.063") diameters.
The scalloping on the walls looks like no appropriate finish pass strategy was used. On MeshCam, IIRC, a waterline pass will do this. On Fusion360 or Inventor, the 2D-contour tool will do it. This is intended to take off a minimal quantity of material so as to control tool deflection and chip loading to get the best finish you can. TOO shallow may allow the tool to rub rather than cut, and this depends on the material and the rigidity of the tool/machine. On something like POM (Acetal) or PMMA (acrylic), ect., a little more radial engagement might be needed, as the material will deflect under the cutter. The side of the cutter can leave quite a fine finish.
For the bottom, you can likely improve it by taking a light finishing pass, but you will probably need further finishing work to get rid of visible texturing from the corners of the tool and, possibly, swirl marks. THis is just the nature of the beast, and is a concern no matter what the machine. The better the finish overall, the more these marks stand out. This is one reason why many parts have an intentionally grainy or textured surface: to hide imperfections.
In general, the LARGER the tool, the better the finish, within the constraints of machine power and part geometry. Unless you need to to get into a small corner, I would avoid the 1.6mm tool and stick to the 3.2mm. This reduces deflection and tendency to form deep scalloping, as well as allowing the higher surface speed needed for a good finish.
The surface speed at 10000RPM for the 3.2mm tool is 100m/min (300 ft/min) which is in the range for aluminum with carbide, and reasonable for a finish pass. The 1.6mm tool will be about 50m/min, which is the low end for Al, and, in my opinion, a low for a fine finish.