[Replicant]

No. additional.css is just for css. Easiest way to add the script is in an ad module. Open site-builder, drag the ad module down on the page, paste the code above in the ad module editor enclosed in script tags. You can also add the code via template hook if you want it on every page.

<script>$(document).ready(function(){if (pageData['pagetemplateid']== '93');
$('body').css('background', 'red');
});
</script>

And on your second question, you almost had it in example two. The braces go between the parenthesis.

.css({
      "background-color": "yellow",
      "font-weight": "bolder"
    })