As you could see in the list of extension, RSFormPro can NOT be share between websites.
Go in the JMS tools and click on help buton or
www.jms2win.com/component/content/article/135
The architecture of RSForms does NOT allow to share it.
So the plan is that we can NOT share it as long they are connected to the core joomla tables.
So I think it would be difficult with rsformpro to share the forms.
You have other extension that can be shared like ckforms but that will be probably less sophisticated but has the advantage that it can be shared.
When you share an extension (any one), MySQL (not jms) take a snapshot of the MySQL table definition. That mean that when you are using a 'form" component that define table and its layout, you may have to un-install and re-share the extension into the slave site when you change the form layout. As the form is shared, this is not a problem.
With CKForms, we also have developed a special version that we provide on billable support only. This version allow to have a forms with all records and have the shared slave sites that only see the records they have created. This allow for example display in a company (head ofcie) all the leads from all the dealers slave sites leads (when ckform is used to record leads).