I don't trade the E-mini. Simply put, you can answer your question for yourself by answering the following questions:
1. Do I have a methodology in place that I persoanlly know is the best around?
2. Do I have safe and practical margining skills?
3. Do I keep level headed even in the most heated times.
The grade you give yourself in those areas is your answer. I'll also give you something on both sides of the spectrum to look for. You better score better than average on all 3 of those questions, because 90% of all traders fail, and you will be one of them if you have a low score in any one of those departments. The other side will give you something to look forward to. I make a lot more than that. But, it is experience and paying the price for what it took to be an excellent trader. It comes from a better than average understanding of how the markets work. You have to be better than average in order to succeed, because you will also be in the upper 10% of all traders if you make it. There is no need to apologize when you reach the upper echelons. You will have a good time at the bank.
BTW, through what you have written, you seem to have done much of your due diligence already, therefore, you are off to a good start. Don't leave your demo trading until you know you are ready to go.