Suggestion: what if you create a separate page for post submission, and use plugin which move their posts into your blog/post page, allows you to set as to pending to restrict automatic posting into your blog page. see plugin link below
https://wordpress.org/plugins/user-submitted-posts/
OR
https://wordpress.org/plugins/really-simple-guest-post/
I have already done that using WP-User-Frontend
but I would like to show their posts on their wall, as if they were wall posts.
I would also like to disable the wall posting feature so that I would only allow them to post through the custom form.
Is that possible?
the plugin will automatically show their post title description(s) along other things they do in their activity/wall stream. But disabling the activities post feature will cost you losing all changes in your future upgrade. More also, the steam is tied to every activities buddy member involves in, probably you need only membership plugin to achieve your aim to less complexities. Goodluck
