You can not assume blindly that revenue from buyers will be good eoungh for you to stop any other earning activity. Better play it safe, and do not make risky decisions without making sure that risk is somewhat limited and that there is PLAN B just in case.
We will see... my living costs are very low. I expect early access sales to be enough to sustain me while working on the game full-time when we get to that point.
However I still want to take the time to make sure its fairly close to completion (everything on the first list) before I release the first early access version, and TRY to keep the time between early access and full release (version 1.0) to a minimum.