Maybe try breaking the original continent into several irregular sections (on separate layers, but still forming one continent), first, and then just sliding each of the sections outwards a little bit, like the continent was cracked and sent 'outwards'. And then throw pretty much all the aforementioned ideas on it, with especially the idea of the ripple effect near the "center" of the spread. Might want to rotate some of the continents, slightly, as well.

As for the tectonics, such a scenario would be nuts, at best, I think. But you said you weren't worried about that, so I'm not sure how much it matters. If you're worried about Dan Browning it (http://tvtropes.org/pmwiki/pmwiki.php/Main.DanBrowned), just throw some oceanic ridges and trenches in the gaps and say "Eh, close enough; I blame the wizard."

-asp