If you ask me #6 is the only one you need #6 builds on #5, so you need that too. #5 would be a good first milestone, so that is #2. A list of your milestones

If you ask me #6 is the only one you need #6 builds on #5, so you need that too. #5 would be a good first milestone, so that is #2. A list of your milestones would be a good foundation for your business plan (#1).