Good morning @Jacob-T,
Your number 1 bullet is spot on. Depending on what your business is, you should never leave a good thing. Meaning, a steady paycheck, insurance, a 401K, if you're earning those things now.
When you start out, your venture should be doing so good that you can't keep up with the demand and you're at a point your ready to quit your regular job.
Don't forget, you may hate your current gig, but it is a steady check, you may have insurance, you may have a retirement plan in place.
A new business will take about 7 years before it becomes self sustaining with reoccurring income and a steady flow of a customer base.
During those years, you will struggle to get health insurance and it will take almost all of 7 years before you can contribute to a retirement plan.
Your second bullet is more troubling to me. 1/3? 1/3 of nothing is nothing.
Depending on what your business is, an arbitrary figure can be misleading and deceptive.
If your providing a service, then your investment will be your transportation to and from your customer's. If your manufacturing widgets, then you have the cost if raw materials, packaging, and shipping costs. If your selling widgets, then your costs will include inventory, storage, and shipping.
So assuming your already "doing" your business, you should find yourself in the situation I described above before quitting your current job.
Your need for capital should not exceed your budget to stay afloat. The biggest mistake in business is borrowing money to sustain and live on. If the business cannot produce enough profit to keep the doors open and pay you something , then you should consider trimming expenditures and maybe even closing doors. I cannot emphasize the fact that taking loans is a slippery slope that will lead to failure. Your creditor's interest rates are enough to kill your profits.
So start small, start out slow, and put every effort into seeing your business grow. If it is successful, it will grow to the point you'll know it is time to make it a full time gig.
By the way, place an ampersand in front of the name of a user's name if you want to address that person directly.
Much success in your new venture.