We tend not to disclose it ,but it is not a huge amount.And we can also limit permissions on an individual basis if there are any questions of the members integrity before permissions are given. If I said hey it's fifty, a spammer would likely hit fifty posts answering yep or whatever to begin his attack.
The warning is issued so people don't go to the trouble to work around the restrictions. The mods are more than happy to post appropriate materials to someones threads if they forward it to firstname.lastname@example.org
and notate their username and the thread to which they desire to attach it to.It may not appear instantly as we are all volunteers here and have regular jobs as most here do.
As for why these limits to new members? In the past we had new members who would post things that you wouldn't want grandma or your children to see, so posting restrictions to new members had to be instituted.It is only a temporary inconvenience to most members,but keeping this a safe palce for everyone far surpasses the need to give a new member instant privileges.And once again,the option to forward links to articles and photos has always been there to each and every member,so no one is excluded completely unless they do not wish to temporarily take the extra step.
And admins read a lot of the posts,but not always each and every one. By not confirming is not the same as affirming a post.