Yeah I've seen similar rusting on mine too.  Huge chunks of paint flaking off the driveshafts and ARBs and looking pretty rusty as a result, but otherwise it all looks solid still.  Those parts are so substantial, they're not going to snap any time soon, but it does look ugly!  I guess the long offside shaft and the arb flex a lot, so cracking paint is inevitable.  Same with the coil springs.
Yeah same with mine.  The rear is getting desperate.  Many of the bushes are shot and knocking, so that's a job for the summer.
Is that DSG cover not replaceable?  I'd be tempted to do that personally, or remove it and get it powder coated maybe?