The meat of your script, sys.dm_exec_query_stats, gives you performance data for cached query plans. The results are fairly straightforward:

text: this is the text of the batch identified by...

Sure thing.

Here's Microsoft's extract page and example... I don't actually like this one, but it is what it is.
SQLStudies.com actually just posted this yesterday.

Just schema?

You can extract a dacpac of your database without much powershell code or from the command line. Either of those methods can be set into a SQL...

Something like this will generate all the create statements...

SELECT 'CREATE TABLE ['+name+'].[YourTable]
    (
        ID INT
    )
GO'
FROM sys.schemas where principal_id = 1

Then you'd...