Barbell Push Press is the best exercise for building muscles...
It depends on the fighter. Some, like Jones and Rousey make good money, but fighters down the pecking order make can make 1-6k...
Weight lifting straps attach the weight to your wrists and help improve your grip.
MMA workouts consist of Brazilian Jiu Jitsu, No Holds Barred (NHB) Fighting, Boxing, Kickboxing, Thai Boxing, Wrestling, Weight Training, Etc.