Is there any easy way to export all the data collected for a specific form??
Not that I know of.
best option I can find so far is to access the database via phpmyadmin > export the database to CSV > lookup the IDs for the various fields in the form. Painfully slow and teedeous, but it does allow you to get at the data.
Once you understand the relationship between the tables you can always craft a query and a script to export it for you and dump to to a comma delineated file.