Trade Size Help

I recently set up an account with $50,000 to auto trade positive forex. The developer recommended "account set up: 50:1 leverage(you should receive daily interest) how to choose trading size? i shoot for 10% a month,so if i have 10,000$ account ill need to make 1000$, lets assume 500 pips average monthly gain,in that case in order to get 1000$ i need to trade 2 mini lots(this wil be one trading size) every trade is one trading size,the max open at any time will be 5 trades"

Please help. Should I begin trading 10 mini lots (5x the recommended for a $10,000 account? Also, could some of you more experienced traders council me on the 50:1 leverage. Is this reasonable, safe or what? What exactly does it mean, and how does it work? Thanks for any and all imput.