I am licensed and insured and work part time (sort of) though it still seems to be at least 40hrs a week with all he estimates and paperwork. I have class 2 days a week for my masters. I typically do jobs 3 days a week and it seems to work out ok.
If you end up going solo, just keep your overhead low. If you are really conservative you can get a couple saws, a chipper, 1 ton dump, and stump grinder for around 10-15 grand. They wont be pretty but they will do the job! Mechanical skills... or a father in law who is a mechanic... is always helpful
Also, don't do anything crazy like financing new equipment!
As far as insurance goes, a 1M$ liability policy for 200-300 bucks a month is not a ton to spend. One job pays for it easily.
As for the worker's comp, you only pay when your workers are working, i.e. a percentage of what they are making (though most companies have a minimum nonrefundable down payment of a few grand). Just make sure you consider it in your bids. Some states its 20%, some it's 50%. I would guess Florida is on the lower end.
Also, get a payroll company or your bank to set up payroll taxes. I use Bank of America and it only costs me like 35 bucks a month. It does paychecks with deductions and shows me how much to pay for my monthly payroll taxes. All you gotta do is click the mouse and there your bennies go!
Best of luck,
Mike