How to Create a Forum in Weebly
If you are planning to use forum in weebly, consider Nabble or Lefora forums that lets you embed the forum in weebly using custom-html element. Read this carefully if you are looking to use the built-in forum for weebly. The provided Tal.Ki forum element is an ‘Integration of third party forum Tal.Ki’ into weebly. What you get with the forum is the limited version of Tal.Ki even if you are a weebly-pro customer. Number of sub-forums is limited to 5. Number of topics is limited to 15. Only the latest 15 topics will be displayed. If you need more than that, you will have to upgrade with Tal.Ki which costs atleast $5/month extra. Instead use Nabble Forums or Lefora Forums. You can embed both of them into your pages. Their embed is as good as or better than Tal.Ki.
The Tal.ki forum element provided should be viewed as integration of Tal.Ki to make it easy for Tal.Ki subscribers who want to use it in their weebly site.
If you really need a good forum, you will need to venture out for alternate choices. Also note that migrating content from Tal.Ki forum to some thing else might not be possible. Check Tal.Ki pricing before taking the plunge.
Including it as a normal drag-and-drop element gives the opinion as though it is free to use. It should instead have been put in a separate third party plugins page indicating that special conditions/restrictions from the provider apply.
If you are ok with 5 sub-forums and 15 topics, then you can install the forum. Weebly has a good documentation about forum usage at http://kb.weebly.com/create-forum.html