4) You can work 2 days a week at a company and do your research at home for the remaining 4 days
You could start freelancing(there are sites like http://www.vworker.com) and work as much as you want/need to live comfortably. If you have a lot of knowledge you can make good money consulting. I think you can make enough for a living if you work at most 30 hours per week(this would be 3 days x 10 hours). That gives you another 4 days of free time per week to focus on whatever you want to do.
Great answer!
I want to emphasize the following:
You could start freelancing(there are sites like http://www.vworker.com) and work as much as you want/need to live comfortably. If you have a lot of knowledge you can make good money consulting. I think you can make enough for a living if you work at most 30 hours per week(this would be 3 days x 10 hours). That gives you another 4 days of free time per week to focus on whatever you want to do.