Is there a plugin to to remove the postbit website url for people that added a website to there profile if they do not have a set # amount of posts?
Maybe exist something like that, but i think if you go to your core files and add a var for url or website var to make a conditional can works.
Example, you call your website in your template can see the value, $user['website'] for example, you can search this on core file and make a conditional of user var of numposts.
if(mybb->user['numposts'] >= 30){
$user['website'] = his value on your core file
}
else if(mybb->user['numposts'] < 30){
$user['website'] = "You have to make 30 posts min to see this content";
}
If you want to use on profile field you can use something similar and put error message or something like that.