It does support rich text. However you need to know the formatting of Wiki's (for hyperlinks just type them in - hyperlinks ending in .gif .jpg .jpeg or .png are rendered as images, lists are preceded with multiples of 8 spaces).

'''bold text'''
''italic text''
!heading 1!
!!heading 2!!
!!!heading 3!!!
        * list item
                * nested list item
||table||with||three columns||
||second||row||of table||

What is really needed is a Wiki sandbox, so you can test out the Wiki features. Also if you give too much control (i.e. change fonts, sizes etc) you lose control of how it looks - Wiki's should have a consistent look and feel about them.