Reality check question: What do the team members get for launching your business while you are still working?
In other words - while you are avoiding taking the leap (aka risk) and they are building a potentially viable business for you to transition into once it's safe to quit your job - why do they need you?
It's certainly possible to launch a start-up while working (though I'd suggest it's generally slower doing it that way - and sometimes slow kills)...
But my experience (personal and via my coaching clients) suggests that a start-up requires several things that you will not be able to provide if / while you are still employed and working a full-time job.
Things like time and energy that will be VERY challenging to put in while you are working.
And if you still need the income from a J-O-B then how are you going to fund the start-up costs? To pay the team? To invest in your start-up in the areas you discover offer the greatest ROI?
I respect your desire to move forward with a start-up (it's an incredibly exciting move!) but I'd suggest you get a solid strategy in place to do so to ensure the greatest probability of success.
I wish you the best of luck!