How do I balance story with the product/features/commercial?
The balance of story and stats is a hard line to walk for sure. My preference and personal inclination is towards story but many of our clients do want more of a commercial, and in many case, that is what is best for them. So we're always trying to be aware of what is best in each case and balance story with a commercial–which is what you see in iAuditor for Gold Corp.
The best thing I can say is that not everything has to be a story. Nor does it have to be a full blown continuum. When we dive into People we move towards story. When we focus on Purpose, we pull towards commercial. Always balance those and always, always, think of the viewer first. Craft for them and they will help you find the answers.
I'd also recommend taking a look at my blog article about producing effective video tutorials through our storytelling principles here.