I've been told I sound a bit Guinessish but I'm not young :-D
I also do a passable McDiarmid (not that his TPM performance needs work done on it it's one of the film's few saving graces).
Maul would be good. He needs more lines.
I think the character of the Feds was sort of right (they are being led to the slaughter with the promise of advancement) but the fake Japanese accents are very offensive.
London Bankers are much more believable. Think Bullington Club.