The updates are definitely included, and you don't need to buy anything again. Anything you download from the main page will have the latest version. What you see in the devlogs is just what has been updated. A thanks for your support!
You might find some examples in blend files if you bought the Source version of the pack. Other than that, we only have the images available here on the itch main page. But I'd say, try take some inspiration from real road networks and build it based on it
