You've done a great job outlining the most important aspects of a business plan!
Here are two really great articles for How to create a business plan
and Developing a business plan
from LegalNature's website. I've found them to be really helpful and all of the information is laid out and explained so well. A lot of the advice they offer coincides with what you've said.
Just a few things they outline that should be included are:
- Your products or services
- The status of the overall industry in which you will compete
- A thorough marketing analysis
- Productions and quality assurance strategies
- Financial information
- The all-important executive summary
But the articles go into greater depth on all of these