There have been many posts about how to hide an optional section (use Conditional Formatting). However, there is one big catch to this. If the section has not yet been inserted, the insert optional link text will still show up. So then once you click it to insert the section it will be ultimately hidden! Ha!
To work around this you have to wrap the optional section in a plain section (bind it to to the immediate parent node) and then set the condition on that wrapper section to hide it all.
Shiraz Cupala / Microsoft InfoPath MVPQdabra® Software / Streamline data gathering to turn process into knowledge