First welcome to CrossFit. I have a little experience with wrestlers and CrossFit.
1) Whether you can add CrossFit into the mix would depend on how intense the workouts are. My son continued to CrossFit 4-5 times a week during the season after practice, and when it wouldn't interfere with meets or tournaments. The caveat is that he was an experienced CrossFitter and has been at it for a little over three years.
2) It is never safe to just jump into CrossFit. In fact it is possibly more dangerous for those who are "in shape" than those who aren't. The threat of Rhabdo should be taken seriously. Beyond that though, the people that scale the workouts and start slowly are the ones who make the most progress.
3) Unless you have a crossFit trainer to guide you, it's always best for newbies to follow the front page for an extended period, that way they are not creating workouts that focus only on their strengths, and ignoring their weaknesses. You'll get the most out of adding CrossFit by doing this. If you are interested in wrestling based CF workouts later let me know. My son and I make a couple up every week.