Re: Too big for 2003 CBR600RR?
for someone your size, crowding is unavoidable.
since you have long arms, you won't need the risers; but, the adjustable rearsets should help tremendously. (adjust them down and back)
i'm 6'4" too and started on a RZ-350 (two stroke street bike) then moved up to several 600s. wrecked all but the last 600, btw. i'm now on a 929 and it still it feels small, yet tolerable.
although you'll always be tempted to let your bike run, don't. take it very slow. just putter round town and put as many miles as you can before even thinking about going fast. you need to develope an intuition on how the bike reacts in demanding situations; and consequently, how you react.
try not using the rear brake unless you get into trouble.
take it slow, you'll be fine. sure, an ol cruiser would have been better to learn on. but, hey you found a great bike!