I use Humana. I'm single, 38, male, in good shape, non-smoker and I pay ~$180 a month for health insurance.
Get a high deductible. A low deductible is nice as part of a group plan, but when you're not on a group plan you're just over paying for extras. Instead, get a health savings account (HSA) and save income (tax free) for the purpose of paying for your health services before you meet your deductible.
Keep your health insurance primarily for major issues. You want insurance there if you get cancer or you're involved in a life threatening accident. You're better off paying for the minor things with an HSA.
For International travel, get travelers insurance. I spend a lot of time in Asia and I use FrontierMedEx. They'll pay your doctors fees in cases of an emergency and will fly you back to the US if you need major care. You only pay for travelers insurance while you're traveling and it's reasonably cheap too. I pay less per month for FrontierMedEx than I do for Humana.
100% of my income comes from freelancing. I build web apps and APIs in Node.js. I charge an hourly rate and I bill once every 14 days. I only take on projects that are going to be at least two months in duration and I give my clients 14 days to pay after being invoiced.
I don't usually have much spare time, although it's not because of my billing practices.
If you're doing projects that are only going to last a week or two, just get 50% up front and 50% on completion.
You're in the right to leave the code online as a part of your portfolio so long as you didn't sign a contract with them and they didn't pay you for the work.
You should, however, not include their company name in your code or descriptions.