To the op, should you personally start a tree business? I've got to say no. You just have no experience in the business. Cutting firewood and tree removal or trimming are two completely different animals. My old man has been logging his entire life, yet i don't ask him to run rope for me on sidejobs simply because although he is very knowledgeable about felling trees, dropping a tree in a postage stamp sized area takes a completely different set of skills. I also don't agree with picking up a bucket before a chipper-most people don't realize how much brush a tree will produce and dicing it in the back of a pickup is no fun for anyone.
But i'm not even going completely say no due to your lack of experience. That can be overcome with picking up a good treeman like others have mentioned. (I'm not going to say you just need a climber, cause you need an all around treeman, someone who can climb, run a bucket, and trim or do a removal from either. Not all climbers are bucket operators.) And so your need for a treeman is going to hurt you. A good treeman can be hard to find. A guy you trust to basically run your company can be even harder. If he doesn't feel like showing up to do a job or calls off because of a hangover, are you going to climb the tree? Nope, and now you've let down a customer.
So, you are looking for a good treeman, dependable. But what do you have to offer him. Many, many of the good, dependable treemen have gone and started their own outfits. There are still some dependable guys around though who prefer not to run a business. But, how are you going to attract him? I got to thinking about this personally, could you lure someone like me away from my current job? Could you guarantee forty hours a week, a weekly paycheck that won't bounce, dependable ground guys, dependable equipment, actual treework throughout the winter (none of this snowplowing crap), full health coverage and retirement benefits, or even a salary close to my current one. That right there is the problem, the dependable guys that don't have their own business are usually in a position or are making a wage that you can't hope to match.
Anyway, good luck whatever you do.