I do not wish to intrude upon the domain of the development staff, but as best as I understood their responses, it seems that they find an option to pin a post in a thread to be superfluous, as this is information that generally should be included in the OP post. If this is not possible, they recommend asking an OP to edit in new information to an OP. As for the duplicate images, they also do not see this option as desirable. Duplicate images make spamming a thread much easier, and makes for lazier and less creative image selection. Perhaps the devs can add to this or correct me.