I shoot for a hobby atm, but would love to go pro.. what better occupation allows you to watch the game you love and get paid for it?
Your certainly right about the 2X converter disadvantage (in England) no doubt you will be fine when you get to SA... its the same in Australia... where light conditions come summer time are fantastic.
Love the last shot you posted, you got it just at the right moment, a millisecond afterwards and you would have missed out!
It is harder living in Australia (as opposed to England) in taking sports photographs, in that there are no-where near as many matches being played (at domestic level) and the venues are hours away -Melbourne Cricket Ground is the closest venue from South Australia...over 8 hours drive.
As I am from England I find that there is nothing quite like English grounds, I fondly remember going to Blackpool (Stanley Park ground) lazing back on a deck chair whilst watching a Lancs v India 'A' match in 2003 -and getting burnt to buggery!
Best of luck with your photography... on what is the greatest game on Earth!
P.s: I have also given some of my photographs to cricketers (Warne, Langer, Lehmann etc) at my own cost... they do appretiate it and a little generosity goes a long way.