My friend I have gone through some of these similar situations.... in a pinch in theory you could jb weld a screw into the cast knuckle... but the CNC are the only way to go when racing!!!
As far as the arm being chewed up... you should run center out-put yokes and you will not have any future problems...
Call the CEN guy ralf and tell him you need a free sample of center out yokes for the front- he gave me mine