Disable "All in one Seo". And check. Also two SEO's in wpForo are not needed.
This is a good point, although if you are using the remaining functions of WordPress (blogs, etc) then you will still need two - just make sure that they don't "cross paths"
If your SEO plugin supports "exclude" urls then the base page of wpForo should be excluded. If your SEO plugin doesn't allow that, you can disable the wpForo plugin internal SEO.
Personally i use the excellent and light SEO FRAMEWORK and i disable wpForo internal SEO.
Also there could be another issue for "lag time".
I see once the topic/post is submitted the "Subscribe" button becomes "Unsubscribe" on your websites. It seems you've activated the "option to keep checked by default" the subscription checkbox in editor. If if this is not true, the lag time comes form Email server of your hosting service. When you post a topic or post it sends emails to subscribes. The email server is slow it'll take 2-3 sec to finish. This subscriptions can be Forum and Topic subscriptions.