HELP MY HORSE IS BEING A GOON!?

ok iv got a relatively new horse, he keeps going mad when people leave the arena hes in (which will be a problem at shows) and he also keeps bronc-ing off with me on board (did it with me once...duno how the hell i stayed on :P ) and generally being a ****.and when i say bronc-ing i MEAN bronc-ing...honest to god iv bin riding a long time and i can honestly say that his bucks are HUGE and they just keep coming...and always at breakneck speed :P i adore him though, and dont reckon he's doing it out of badness. people tell me to turn him into the wall, but id rather not as it terrifies me and horses have put their feet through the walls in the indoor before...really i want to know if theres any calming techniques i could se on him whilst riding, on the ground, or in the stable, if theres any feed suppliments which will help calm him without making him unresponsive and dull, or just general tips. i'm in no way scared of him while im riding, just trying to get some diffrent perspectives in answers :) i know underneath it all he DOES want to please me, but just gets excited a tad sometimes. thanks xxxxx