The style builder will support the latest version of the controls; nevertheless, if there are no rendering changes between versions, it will work with older versions. Take it as one more reason to upgrade to a newer version, heh.
Regarding the licensing, it's a free
tool. We prefer to invest our time in creating value rather than hunting customers down. It would be great if you renew your subscription, yes, but we hope to persuade you to do so through delivering great products, not by pushing you against the wall.
the Telerik team