On mine (using AFAM sprocket and original (31.000KMs) plate/bolts, the sideway play is considerable, but I belive it is not as much as yours (not big difference though). When I replaced the sprocket, I belive the old one was original, at least it the bike has been serviced by a Honda garage, there was some red silicone-liquid-gasket-like stuff in the gap, so free play was a bit less and "softer". I just removed this and replaced with new sprocket, and could not feel any siginificant difference. I'm not an mecanic (far from), but have replaced some sprockets trough the years, and cannot remember I have seen this much free play on any bike.
Life is a just a game - lets play!