RE: Add shortcuts to Suitecommerce navigation
The category navigation is dynamically generated and does not include options for manual interventions like the ones you describe.
If you wanted to customise it, I would:
- Replace the relevant template in my theme with a custom one, so that it has a placeholder
- Write an extension that injects a view into the placeholder
- Write my custom view so that it figures out what featured product I want to show (eg perhaps some sort of configuration property) and then loads it in that place