Sure, you can do any of that by simply editing the CSS file.
1) Open your CSS file and create a class for each author
CODE
EX:
.uvalaw2005 {color:blue; font-weight:bold; font-size:12px;}
.doc {color:#000000; font-weight:bold; font-size:14px;}
2) Edit the template and find the spot that says
CODE
posted by <$MTEntryAuthorNickname$>...
or something similar
3) Then just span the the entry with an MT Tag and when you rebuild whatever is inside the span will be formatted per your author class
CODE
posted by <span class="<$MTEntryAuthor$>"><$MTEntryAuthorNickname$></span>
You can do any specific changes this way. I used this method on a blog once to change the background of the post dependant on which category it was assigned to.