Hi,
2.4" stickout is quite long even for carbide. I sure hope flute is not as long. I would suggest checking what depth or cut HSMAdvisor is recommending and going with that.
There is "Performance" slider of the Speeds And Feeds Overrides panel. Move that to to about "x.5" or so.
Regarding speeds and feeds. Actually anything will do. Its aluminum, after all. I would go 5000 RPM and 30-50ipm feed rate.
Good luck.