We use nightly IRIS backups which are moved to a network share, so Test can restore the backups to an alternate application data DB via a script.  We always have 2 application DBs defined, so we can script a restore on a weekly basis so the data is readily available if a developer needs it - they simply swap from the active data DB to the alternate (the alternate is always the target of the automated restore so as not to interrupt any data depending testing which may be actively going on at the time of restore).  

We have found this to be very effective for our needs for multiple internal applications. 

if you are wanting to completely render the page within the context of another page, then using <iframe src="package.page.csp" </iframe> is going to be your best bet.  Remember that a csp page isn't just a static HTML snippet - it is an entire renderable page, along with pre-page headers, etc.  That is why OnPreHttp(), OnBody() and OnPostHttp() are all included in the page framework for a .csp.  If you simply want to show what is 'rendered' when you call the page directly, you can play with calling OnPage() (which contains the compiled version of the entire body of your .csp file), but that may not operate correctly when called in isolation - it is intended to be called as part of a full pageload process, which the iframe approach above would provide.

I want to re-iterate what Evgeny said ... you should never store your persistent objectscript class definition in source control without the storage definition block.  Doing so will cause the storage block to be regenerated from scratch each time source is loaded, and if there is existing data you may have a mismatch of where properties exist on disk and where where the source thinks they should live