I think what you are looking for are templates.
In CQ5, templates can be used to create pages with a predefined content, this can be a parsys (with components) or any other node you might want in your page when it is created.
In your case, you can define a template that includes a parsys component and whatever you want inside that parsys. You can also set rules for where a page can be created using that template.
After you have created (or edited, since you might already have one) the template, you can use the siteadmin to create a new page using your template. The page will be created and all the content below the jcr:content of the template will be copied into the new page. You can even have several templates for the same kind of page, if you need different types of 'initial contents'
An example of a template that includes a parsys with some content might look like this (I'm writing this mostly from memory, might have errors):
<?xml version="1.0" encoding="UTF-8"?>
<jcr:root xmlns:sling="http://sling.apache.org/jcr/sling/1.0" xmlns:cq="http://www.day.com/jcr/cq/1.0" xmlns:jcr="http://www.jcp.org/jcr/1.0"
jcr:description="A form"
jcr:primaryType="cq:Template"
jcr:title="A form"
allowedChildren="/apps/app1/templates/home_page"
allowedParents="/apps/app1/templates/form_page"
allowedPaths="[/content(/.*)*]"
ranking="{Long}100">
<jcr:content
jcr:primaryType="cq:PageContent"
sling:resourceType="app1/pages/form_page">
<parsys
jcr:primaryType="nt:unstructured"
sling:resourceType="foundation/components/parsys" >
<component
jcr:primaryType="nt:unstructured"
sling:resourceType="foundation/components/text"
text="here is some text"/>
<!-- more components here-->
</parsys>
</jcr:content>
</jcr:root>