Have fun in jail!
It doesn't matter if you own a pizza palor, mine bitcoins, or sell drugs.
You always owe taxes!
Why don't you move to a country where there are no capital gains tax and no income tax.
As long as you live in the US or are an US citizen you will be breaking the law and the IRS will catch up with you.
Plenty of cash only businesses under-report their earnings. Some get caught, many don't. If you know the tools that the IRS uses to catch these types of tax evaders (I do) it would be easy to keep your BTC-to-cash transactions under the radar and get away with this indefinitely. Even with a random audit. However, if the IRS for some reason or other opens a criminal investigation on you then it is a different story ...