> but nothing matches the joy of working for yourself at your own pace.

That's the opposite of how I would describe freelancing. You aren't working for yourself at your own pace, you are working for your clients at their pace. Rather than having one boss, you have multiple bosses. Sure, you can pick your projects and have the client agree on a timeline you set, but I assume you can do that on the job as well.

That work doesn't include the time you need to spend on marketing, branding, creating proposals for jobs you get passed over on and a long list of other things which you don't have to do when working a typical job.

You might think you would have more freedom as a freelancer, but that's often not the case. If you could charge high rates and live super cheap, then this would largely be true. But living super cheap often means that you are living in an area which makes charging high rates relatively difficult (you can't get that "face time" which certain clients require, which means you have no leg up on your competition which might be charging less.) This is where your marketing really helps.

As a freelancer you will likely find that you are working more hours than you were at your job. Every hour working is really working. I can only put in about six hours of coding per day because I'm at such a high level of focus. At your job, you may be there eight hours, but how much of that time is spent truly working? Again, on top of that time spent on client work, you have other non billable tasks you have to do for your business. And since you are still trading dollars for hours, you still have that ceiling of 24 hours per day.

Another point that I believe is critical to consider is that there is a lot of gray area between freelancing and working a regular job. For some people, the only difference is in the forms they are having to fill out for taxes. I have had long term freelance gigs which were basically jobs. And people who have jobs should probably be marketing themselves just as a freelancer would. If you find this describes you in your freelancing, then you should probably just stick with a regular job.

Instead of freelancing, you would be better off removing that word from your vocabulary. Instead, shoot for running a sustainable business which doesn't live and die by your hourly work. Do some Googling to find case studies of people like you who have been able to move on to different business models, or at least supplement their hourly work with other forms of income. You aren't truly your own boss until you are able to earn money while on vacation or sleeping.

To answer your questions:

When to make the leap?

As the other comment mentioned. You need to have at least 3 months living expenses, but once you dip below that, you are approaching critical levels. You should have at least 6 months, but the more the merrier. This is so important as the lower you get, the more desperate your cash flow situation becomes. The best case scenario is that you can plan out months, maybe even years rather than having to worry about what you are going to eat tomorrow.

You should have a decent amount of experience built up, but a lot of people make the leap without this. I think there is a market for all levels of experience. A lot of freelancers go that route simply because that's the only way for them to get work as a developer. You do what you have to (and this applies to the financial part also.)

How do you manage your time and what to do when you don't have work?

There is a ton of work out there. I rarely if ever hit a point where I have nothing on my plate. If I do, it's because I'm between projects and in this case I can still take on small stuff.

Time management is something that is different for everyone. There are tons of tricks out there. Google it. ;)