Sadly this is not the understanding of GBIF, who will not accept copyrighted observations, so those are lost for many scientific uses.
One would think so, but each observer can select three separate types of license - for the observation itself, for photos, and for audio (see Account Settings - Content & Display - Licensing). This causes considerable confusion.
I agree it’s a good practice to acknowledge identifiers, as in many cases their contribution to unusual records is essential.