to make featured products go away forever,
you can simply not assign any.
to idiotproof it from your store, you can comment out the entire template, /skin1/customer/main/featured.tpl
Code:
{* {capture name=dialog}
{if $f_products ne ""}
{if $total_pages gt 2}
<br />
{ include file="customer/main/navigation.tpl" }
{/if}
{include file="customer/main/products.tpl" products=$f_products featured="Y"}
{if $total_pages gt 2}
<br />
{ include file="customer/main/navigation.tpl" }
{/if}
{else}
{$lng.txt_no_featured}
{/if}
{/capture}
{include file="dialog.tpl" title=$lng.lbl_featured_products content=$smarty.capture.dialog extra='width="100%"'} *}
but -- if you don't assign a featured product, they simply won't display.
Get to know webmaster mode, so you can see what templates are working for you.