Enable WYSIWYG editor in comments (Restricted)

Is there a way to enable WYSIWYG editor in comments for certain member levels; or at least just for admin?

No, it would require custom coding.  One thing that my members have asked for is the ability to turn off the WYSIWYG editor on their pages; such as the profile comments.  The reason is they want to avoid members posting graphics.  I have yet to code that in but it is something on my "to do" list.