Focus on the executive summary. As you execute the plan, you act emergent—that is, you are flexible and fast moving and change things as you learn more about the market.
Life is not clean like that. If you are doing a pitch on a demo day, you typically have 4 minutes, not 20 minutes!
The only time you will do a presentation is when you are pitching a larger firm and you present to the full partnership. They are wrong. Think of your pitch as an outline, and a business plan as the full text. Keep it clean. Force yourself to use no font smaller than thirty points.
The executive summary, all one page of it, is the most important part of a business plan. Unsubscribe at any time. Many people believe that the purpose of a business plan, like a PowerPoint pitch, is to create such shock and awe that investors are begging for wiring instructions.