I think it would be BEYOND bad, and edging towards bowell-clenchingly awful.
The "zany", "cheeky" ex-double-glazing-salesman-from-Stoke-turned-manufactured-boy-band-member-turned-"respectable"-manufactured-solo-artist playing Jimmy B...NNNNOOOOOOO!!!!!
Blood....pressure.....rising....must....cease....and....desist.
I mean - I know that James Bond doesn't exactly have any "credibility" anymore (if, indeed it ever had any), but I still like the movies...they're like settling into an old armchair - you know what you're gonna get - it ain't original (only the stunts/actors/locations change), but it's a constant - putting that little oxygen-thief in the role would mean one less guilty pleasure for me to enjoy.