i'm worried too... it's the only one of my v.2 valks before the Max 1S that i haven't removed the knurling of the pin on. so far it's still okay.
i may be putting too much faith on that message from Yamato saying they told their factory workers to be gentle when inserting the pins...
i read somewhere that OD increased the s/h they charge to get these replacement parts... anyway, the bonus arm assembly is okay, but who's actually going to use it? (except maybe, for using it for funny action poses like w/ that old VF-0S pic of yours ) ... and i also read that the arm assembly doesn't come w/ the hand...