
uh oh....I'm staying out of this one....two threads were shut down yesterday because "idiots" (I'm one of them) weren't sternly opposed to a newbie possibly starting on a 600...we idiots were trying to take into consideration some factors you mentioned (and others) such as inherant coordination, strength, feel, learning ability, experience trying other new and similar hazardous activities, and other characteristics only the person themself can assess. To put it another way, our/my take was that it depends on the intentions of the person, how much of clue they have, how coordinated they are, and how much of an accident waiting to happen they are...basically. But, maybe the default answer would be that a newb should not start on a 600. Guess I'm not "staying out of it".....I may have just ticked of a lot of people...oh well...Gotta speak your mind!
Anyway, good luck with your decision...in terms of potential problems, they're all over the place. It's all about feel, staying within your limits, looking out for hazards (i.e. road hazards - gravel, oil, potholes, etc. - and human hazards), knowing the throttle and brakes, they're application, how strong/touchy they are, smooth shifting, cornering technique, watching your entry speed, low-speed maneuvering, and alot of other things. And you always want to ride with the assumption that no one around you has a clue that your there. Don't ride next to cars, that's known as the "death zone".... and stay out of car's blind spots. At least that's my take on it. Again, good luck, hope if goes well for you.