Part file: Attached (note the unfinished pattern is suppressed so use tree filter to see it and resume it)
I have to create a pattern around a mold cavity that is going to change so it needs to be able to update plus I have others to do so I need to know the best practice for it.
was able to make the outer cut by using the Offset>Chain command. I also made the joining cut 2 ways by drawing a sketch and by using a "thicken" line extrude, because of the following issues to see if one would work better (turns out it does not matter).
Unfortunately, I don't have time to take a long look at this but when creating the patterned sketch for the "spoked" vent cuts, you will need to create a horz/vert reference that will pattern along with the points (you can group and then pattern). This will force the cut to "rotate" with the shape of the curve.