When you simulate, you should see the result (turn off the toolholder, unless you model it for your setup), but leave tool visibility on, and turn on stock visibility. UNLESS you change some of the defaults in a strange way, or do something careless in setting up the operation, none of the machining strategies in Fusion will remove material that shouldn’t be removed.

If you prep the material as a disk rather than a square profile, that will save a lot of machine time, but the additional prep time will likely be greater than machining time saved, unless you are running a lot of parts. Check the settings and match them to the material, but 30 or more minutes is reasonable. You are removing a lot of material with a small tool. The time depends on the radial and axial engagement of the tool, as well as the travel speed. You want to let the tool go outside the boundary of machining to get all of the way to the bottom of steep vertical walls at the outside of the part.

The stepover (spiral) and stepdown (contour) should be selected for the cusp residue you are happy with. Then, I would use the ball end to do finish passes using contour and spiral (spiral is for regions less than about 45 degrees from parallel to the x-y plane, and contour is for those more vertical than that… It has to do with whether the horizontal step or vertical step is dominant) Use spiral for slope from 0 to 45 degrees (slope selection is in the second tab), followed by contour from 40 to 90 degrees. In Fusion, the easiest (IMHO) way to set it up – not the most efficient, but the easiest – would be to run 3D adaptive over the whole thing using a square nose bit to rough, leaving about 0.25mm (radial and axial) for the finishing. Presuming the side not in view is flat, this is a single setup job, and I would do it with two tools.

Fusion 360 milling