The age restriction will vary depending on where it is that you are competing. Some places ask that you are at least 16 or 18, and some allow younger participants. There will definitely be somewhere your son can compete, so you should look around and see what there is near you.
Motorcross is competed in, all around the world, at various motorcross tracks
Motorcross is popular EVERYWHERE but mostly i would say America and the UK
Well, you don't 'play' motorcross! You ride it, and you do this at any outdoor or indoor tracks.
In the 1800s
British
no
well it depends on who but football players at an average do make more $ than motorcross bikers.
She would have to be at least of legal age to be married.
falling down and death
about 70mph
No, but thanks for asking.
ride dirtbikes?! lmfaoo.