Going blogger full-time? When to quit?

I’ve had this discussion on and off with a lot of my friends and my family members. I’ve been digging articles all over the net but still have only figured out four main things. If you want to become a full-time blogger or start a small web-business for that matter, what is the right time to quit? My four points (and I’m looking for more – if you’ve never commented on this site do it now).

1. Save enough to survive an year without any income – That’s only an estimate but the point is to be prepared for the worst while hoping for the best.
2. Get rid of all your debts – It works different ways in different societies and countries. In the US pretty much everything is financed. If you consider India, it’s against the old cultural ethics to take loans. But at the end of the day what makes sense is that for that piece of happiness for which you are changing your world, make sure no debt collectors ring up your phone. You have to ensure that this is taken care of before you quit your regular job than expecting to clear it off gradually.
3. Test the sustainability of your business – It’s not how it will work, it about how it may not work. You need to look for the gaps, the cracks the leaks in your ideas and plans. Once you’ve tried a creative mind at the plans, try a destructive one and see how easy you can break down those plans playing your own enemy. Now fill up those gaps.
4. Share it with your close ones – Sharing a plan that you expect to found you rest of your life on needs polishing, grooming and evolving. Share your ideas and plans with your close ones and see if they are able to notice something that you may not have been able to. Slowly your ideas will mature and evolve.

I couldn’t find any other points beyond the ones I mentioned here. Do you plan to quit your job? How? Have you already done it? What would you plan if you wanted to do something like this?