Form families are managed and maintained by us here at GOSS. We release regular updates that add new field types and functionality to your forms.
By default it is not possible to edit, or even view, the various elements that make up a form family, even if your user has the form family privilege. This security feature prevents an iCM user maliciously tampering with the form family, which could potentially impact all of the forms published on your website. You can turn the restricted content lock off via a setting in iCM's autoconfig if you need to import a new form family, but it should be turned back on immediately afterwards.
The form Runtime Information section of the knowledge base has lots of information about form processing, publishing, rendering and the form lifecycle.
Any changes made to a form family will be picked up by your forms the next time they are published.