Newbie - poor auminium cutting, but why?

[routercnc]

6082-T6 if fine as well the stuff you have is awful to cut

Agreed. Also I’ve generally seen thin sheet as 1050 and thick sheet as 5000,6000,7000 series. I have not seen thin sheet at 5,6,7000 series but I might not be looking in the right places. There could be a technical reason for the alloys produced like that or just that thin stuff is often bent and fabricated.