@realjohnboy,
I consider cricket to be the toughest game here. At the top level I mean. Lower down it's more a social activity.
In general all sport is tough and rough.
There are two forms of rugby. Rugby Union and Rugby League. The first is posher. League is working class and northern. In neither is it allowed to tackle a player who is not in possession of the ball. Very few rugby players have front teeth.
Horseracing is pretty tough too. I used to know the British javelin champion and he trained until he spewed up. The training is the hardest part. Rowing is murderous.
It's impossible to deal with your questions in brief.
Like all human activity where there is big money and fame involved there is no room for the faint of heart.
I would say that the toughest place to be in British sport is coming down the hill towards the last three fences in the Cheltenham Gold Cup when there are five or six horses still with a chance. If there's three at the last fence the jockeys take their very lives in their hands.
And there are the temptations of women, booze, drugs and gambling.
But nothing compares to sitting on top of a moon rocket. That's a madness in my opinion.