6082 Aluminium billet test

Ok,
After buying the license for cambam Plus a few days ago, I decided to test some pockets in 76x76x20mm aluminium billets I have.

I used 4mm and 6mm S flute endmills. I had to slow down the feedrates in mach3 as they sounded like they were struggling a bit and I snapped 2 of the 4mm endmills. I used WD40 as coolant, but my compressor broke down so that did not help.
The last pocket you will notice was to attempt to clean up the higher surfaces. The end result for the first attempt in Alu , I thought was'nt that bad. But it left some sharp edges and the vertical sides have a rough looking tool marks, but feel smooth.
Do I buy a dremel tool to smoothen up the appearance or perfect toolpaths ?.
If anyone can adjust my file to make all the edges smoother I would appreciate it, so I can study what the difference is between my original

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