Hi, first of all no you are not crazy. To be a level 10 gymnast and to work out 30 hours a week you need to be the type of person who loves to exersize and train. I can understand that you want to do something outside of gym because you spend so much time in the gym. It is very hard when you train that many hours but it is nice to have another outlet that isn't gym.
And yes other people do do that but not many. When you train that much it is very, very hard to find time to do other activities and still have time for school work, rest and relaxation, social time and so on. But it wouldn't be impossible to find say an hour a week to do something different.
I wouldn't worry about the cardio or strength training, your gymnastics will be looking after you in those area's. I would look for something you enjoy doing like swimming, ice skating, a dance class, a martial arts class or some other type of physical activity that you can enjoy that isn't gymnastics. Most of these actitities you can find a class to do once a week for an hour or so which is probabaly all you could fit in.
How much is too much? That will vary greatly from person to person. You sound similar to me in that you can do a lot more than the average person before it becomes too much. It doesn't matter if you are sore sometimes it matters that you have time to do the things you need to do.
Ask yourself
Do I have enough time to complete my school work to the best of my ability?
Do I feel tired a lot of the time or do I find I have enough time for sleep and relaxation?
Do I get sick of being around other people and need more time to myself?
Do I get tired of having too much structure and need more time to just goof off and do my own thing?
Am I happy with the amount of time I have for recreational activities?
If you answer those questions you will get a good idea of whether or not you are doing too much.
As for losing weight, if you are training 30 hours a week and overweight then exersize will not be the key for you it will be diet. As a gymnast you need a good healthy diet to fuel your body to get through all those training sessions. To lose weight avoid junk food, fast food and try to reduce the amount of sugary things you eat. Sugary things tend to burn up a lot faster and then you get hungry again a lot sooner. But if you are not overweight do not diet. You need to be healthy and fit to survive gymnastics. If you become underweight you will not be able to perform to your best as a gymnast and you will find if you loose weight you will lose a lot of your skills and your gymnastics will go backwards not forwards.
