Can I link to an artist in­side a me­dia cred­it field?

You sure can. Just add the link at­tribute in the media-​credit short­code, found in HTML view for a post, or di­rect­ly when adding an im­age. For ex­am­ple, if your post con­tains:

[media-credit name="Artist" 
              align="alignleft" 
              width="300"]<img src="http://www.mysite.com/files/2010/09/image.jpg" width="300" height="450" class="size-300 wp-image-2" />[​/media-credit]

change it to:

[media-credit name="Artist" 
              link="http://www.artistwebsite.com" 
              align="alignleft" 
              width="300"]<img src="http://www.mysite.com/files/2010/09/image.jpg" width="300" height="450" class="size-300 wp-image-2" />[​/media-credit]

Note the link to http://www.artistwebsite.com above.

Can I dis­play all or re­cent me­dia cred­it­ed to a giv­en au­thor?

In­deed, just call the tem­plate tag <?php display_author_media($author_id); ?> in your theme’s author.php (or else­where, if you want). The tem­plate tag has op­tion­al pa­ra­me­ters if you want to cus­tomize the CSS or text. The de­fault op­tions will dis­play thumb­nails of the 10 most re­cent me­dia items cred­it­ed to the giv­en user float­ed to the right with a width of 150px and a head­er of <h3>Recent Media</h3>.

These op­tions can be changed with a more ver­bose call to the func­tion: <?php display_author_media($author_id, $sidebar = true, $limit = 10, $link_without_parent = false, $header = "<h3>Recent Media</h3>", $exclude_unattached = true); ?>. This will make on­ly the 10 most re­cent me­dia items that are at­tached to a post dis­play with the giv­en head­er tak­ing up the max­i­mum width it’s af­ford­ed. Each im­age will link to the post in which it ap­pears, or the at­tach­ment page if it has no par­ent post (un­less $link_without_parent is set to false). If you don’t care about whether the me­dia is at­tached to a post, change $exclude_unattached to false. This func­tion as a whole will on­ly dis­play me­dia up­loaded and cred­it­ed to a user af­ter this plu­g­in was in­stalled.

I dis­abled the plu­g­in and now un­parsed [media-​credit] short­codes are ap­pear­ing all over my site. Help!

Add this to your theme’s functions.php file to get rid of those pesky media-credit short­codes:

<?php
function ignore_media_credit_shortcode( $atts, $content = null ) {
    return $content;
}
global $shortcode_tags;
if ( !array_key_exists( 'media-credit', $shortcode_tags ) )
    add_shortcode('media-credit', 'ignore_media_credit_shortcode' );
?>

Al­so, I’d re­al­ly ap­pre­ci­ate it if you gave us some feed­back as to why you dis­abled the plu­g­in and how it could have bet­ter suit­ed your needs.