I believe this has been answered about 38024982390 times so far.
Most people take 3-6 months to develop. It would be wise to have money for 6 months. Even if you make money your 3rd month, you wouldnt actually see the money till the end of your 4th month because its in arears.
They do not pay for your trades, they pass everything through.
Only the very best make over 55% of any money they make. Most make 35-40%. Eventually if you are exceptional you will make it to the higher levels and see money over 50% coming to you.
Success rate varies, i would guess between 10-30%.
Good luck, keep your discipline and your head up through training, its rewarding if you suceed.