All fanart should be placed only on the Kunio-kun Fan art page. Please, refrain from removing official artworks (or sprites) from articles and replacing them with fan-made content (especially on infoboxes).
If an official artwork cannot be found for a specific character, or if none was ever created for it, then an in-game sprite is acceptable.
Hope all is well. It would have been nice of you to ask if you can submit my art to the fan wiki. While I more than likely would have given the okay, I do not condone submitting such low res images. XD
Yes. These are auto-generated welcome messages that are posted on a new user's Message Wall after they make their first edit on a wiki. The system randomly picks one of the site's administrators which has been recently active and sends the message under their account.