To change the look and feel of client support center, you need to modify the required templates from:
Admin CP > Templates > Groups > Templates. The associated templates are "clientcss" and "header".
Templates can be modified to hide "Search" bar or Loginbox or Subscribe option.The widgets can be hidden from Admin CP > Widgets.
Client support center logo can be changed from:
Admin CP> Templates > Header Logos > 'Support center header logo'.