I think its better everyone starts brand new, this gives a feeling of a fresh start where everybody is equal. Casher or not casher, you still have the same starting point.
I won't argue against cashers, after all, they're the pillars that have sustained the whole game and its development phases.
As for a reward, I think the game has enough as it is. Just being able to play it again is the best reward ever.
A title wouldn't hurt though xD imagine something like "Beta tester" or something kirito style haha HAHA... ok I guess no