I would agree with Twobets that you need to aim for a realistic amount, like 10% pot so if you bet 100 you want to get back 10, this may bot sound like much but if you could get this on a weekly basis as an average then you can double your bank every 7 weeks.

I don't see any issues with running a couple different systems would be like a portfolio but you don't want to be committing to much of the bank on any given day, so you would want each system to be picking 4 or 5 runners each.

Set your bets to a percentage of bank say 2% with the view to adjusting this at the end of the day, some say you should adjust after each bet but i find this can have more bad points than good unless you are hitting 50% or going after very short prices.