The Kunena plugin works quite well with jomsocial. However, there are a few items for which to take note in order to make the most of it; such as new posts and deleting entries from jomsocial recent activities. For one, a new entry will be published in recent activities on the original save. The only way that I can see to update the entry is to copy the finished entry from the Fireboard or Kunena table named fb_messages_text and move it into the appropriate entry within the communities_activities table which is part of jomsocial. If images are used, they should be transparent unless the forum and jomsocial activities have the same background.
Writing directly to the database via phpmyadmin or using the mysql prompt can also save quite a lot of time creating entries rather than using a clunky backend administrator zone.
Finally, if you happened to leave the forum open for public access, you will notice these entries will show up in the Activities in JomSocial as well. Chances are that if you allow public access, someone will do ‘greasy kidstuff’ like write bogus links and text. Or, some spammers from eastern europe could create a bunch of annoying links. Either way, if the spam gets out of hand, the fb_messages table will leave an ip address of the spammer so that it that can be added to a list of banned ips.