and Rincewind is meant to be pretty young, dammit.

YES. I get that Twoflower is squicky stereotype-wise, and they were probably trying to avoid the squickiness (although whitewashing is a problem too, there's no graceful solution there, Twoflower is just problematic at best), but old Rincewind was just wrong.

Almost as wrong as Tim Curry hamming it up as Trymon.