A modern sport bike just isn't very forgiving. When you get into trouble (and as a noob, you will), the chances of hitting the pavement with a bad (read: rookie) move are greatly higher than if you were on a smaller, easier to flick around bike.
Again I'm going to suggest reading Twist of the Wrist, and whatever your decision is, always check your throttle hand. Snapping it will result in pain. Look up the definition of a high side.
As for riding solo vs. in groups, depends on how you look at it. It's safer in the fact that if shit goes down (ie: you) you've got someone around that will help.
The cons of being in a group, think back to when you were a kid riding pedal bikes with friends. Remember all the stupid shit you did in groups? Expect to do all that stupid shit, with higher probability of getting hurt at higher speeds.
One rule of thumb to follow in a group: ride at your own pace, especially as a noobie.
With all that said - get a bike already, they're a fucking blast.