Many good points already listed. I have owned my own business for years, and continue to do so. For me, I feel that is the only way to make an above average income, plus you are in control of destiny.
One thing I might suggest, is if you are going to have employees, give them some motivation to do well, and be productive. Keeping a job will not cut it. I have been very disappointed with employees and their work ethics. No one will put more time, or have a vested interest as you will. If there is a way to reward the employees based on their work, a piece of the pie, if you will, you will have workers that will make a difference. Give them that incentive. The better the business does, the better they will do.
Also, as much as you will own your company, make sure that it does not own you.
As far as income goes, it is whatever level makes you happy. I used to think 100,000 a year was all the money in the world, until I hung around those making that a week.
Take pride in your work, and the clients, customers, etc will respect you, and you will have repeat business, which should be a huge portion of your business.