First of all, how long did it take you to go from taking the first step to becoming a full-time writer?
I've only been full time for 2 months so my exp is prob less valid than the others posters here, but here's my twopenneth anyway.
What type of writing is your main source of income?
Mostly features for a daily newspaper's supplements, but I do a weekly travel blog post and bits online copywriting.
How do you pay for health insurance?
Good question. I'm in the UK so our govt takes are of us for most things, so far...
What are some of the downfalls of writing full-time?
I'd echo what the others said, social isolation is the big one (but I find things like twitter and facebook compensate a little and my last workplace was hardly sociable anyway, I'd rather feel alone without people around me than with them!)
Also lack of security and doubt, when the email/phone goes silent for even a week I start to doubt my decision. I'd add not being able to switch off sometimes and keeping erratic hours (like now). I work better late at night but this sometimes means I lose a good chunk of the next day. On the other hand I much prefer not having to do the 9-5 and getting up early.
What are some of the unexpected advantages?
See above, also I won a trip to Montreal recently through my blogging. I've never left Europe so it's a big deal for me. I'd never imagined it possible a year ago, nor would I have put the effort in to win the competition. Increased confidence in general. Work is coming through steadily so far without having to chase much, it's nice to feel needed, often in a day job you feel the exact opposite.
Also the editors I work with are fairly undemanding and rarely ask for re-writes. Much better than having to filter copy through a chain of 3 or 4 diff people who chop it about so much that the end result doesn't feel like your own work.
Do you make more or less money now than you did in your prior full-time job?
About half of my earnings of what I made in regular job so far, but early days and I saved for months beforehand to give me a decent buffer. I'm not panicking yet!
Are you glad you did it?
Absolutely. Leaving my job, getting into blogging, going freelance and becoming immersed in social media in gen are some of the best things I've done with my working life so far, and all done in the past 6 months. Many things feel much more possible now, like I'm in control of my destiny rather than drifting unhappily from one unsatisfying day job to another. I hope I don't have to go back but would like to find ways of getting out the house more and making it more sociable.
Best of luck and go for it, when you feel the time's right of course!