Definetly, I have done boxing for fitness and it was one of the hardest cardio workouts ever! Haha
Even if you dont do boxing as a competitive sport it is still a great skill to learn, and if you ever get into a fight you know what to do! Haha
It depends what kind of person you want to grow into. Boxing is a very aggressive style, and thus the people who do it tend to become quite aggressive people. Are you willing to do that to yourself?
Yes, that would be good for you, you would get in better shape, you would travle north america, if you are from north america, and it's realy fun, you would meet some cool people, and if your a boxer your fit enough to be in the army. :)
Next year I'm going to be 15 and I wanted to do something that's kind of rough so I thought I might do boxing. I'm doing it more for fitness / to get into shape rather than actually doing proper fights and stuff so mainly just sticking to training and learning techniques and stuff. Do you think that this is a good idea to train my body and as a recreational type activity?