Hi,
Soma, did you get anywhere with this or should I start from scratch?
If that content.css isn't site specific by default, might aswell try with the following.
Shouldn't break anything from previous installs just by leaving the default empty:
style_formats : [
{title : 'Bold text', inline : 'b'},
{title : 'Red text', inline : 'span', styles : {color : '#ff0000'}},
{title : 'Red header', block : 'h1', styles : {color : '#ff0000'}},
{title : 'Example 1', inline : 'span', classes : 'example1'},
{title : 'Example 2', inline : 'span', classes : 'example2'},
{title : 'Table styles'},
{title : 'Table row 1', selector : 'tr', classes : 'tablerow1'}
]