1.If the download link does not appear on their site you can download the community edition from Sourceforge:
http://sourceforge.net/projects/jcow/files/jcow8/
(Also we have confirmed with vendor that the releases on sourceforge are stable releases)

2. After Upgrade few tables are not getting created i.e jcow_topics_followed, jcow_topic_ids etc
We have discussed with script vendor regarding this and they said that these tables are not required for CE. It will get created if client upgrades to PAID version.

3. Release date : https://sourceforge.net/p/jcow/activity/?page=0&limit=100#59627546e88f3d1360a402b9