As far as software goes:
If you’re doing big aluminium jobs I personally think Fusion360 is the way to go, those adaptive toolpaths work well with the shapeoko, and give you a lot of flexibility
Mach3 is control software, which won’t work with a carbide motion board, unless you’ve upgraded/changed your board then CarbideMotion/UGS/CNCJS will be fine for F360 Toolpaths
Have you done much aluminium machining? @RichCournoyer gave some excellent advice in the second post of this thread
I use similar to the settings you mentioned but only go around 2.5mm DOC. I’m sure it can be pushed harder but I get good results with those settings.
There is loads of great info earlier in this thread from Rich and @Vince.Fab, also in this one , I suggest re-reading the whole lot then starting out conservative and working your way up until you find the limit, then back off 10%