Mike

It depends where you put that code(should be in your header). You could also try an echo statement like this:
'<?php if ($cat) {
echo <<<END
<style type="text/css">
.img_main {
border-style: none;
border:1px solid #E8E8E8;
padding: 6px;
margin-bottom: -10px;
margin-top: -10px;
width: 95px;
height: 95px;
}</style>
END;
} ?>'

though I think that your code should do the same.

Yes. You would need to create files that can connect and modify the new table. Like add-quote.php, edit-quote.php, etc. You could easily integrate this into index.php with another include at the top, like:
<?php include("wp-blog-header.php");
include("quotes.php"); ?>
Quotes.php would contain all the functions/calls you need, so that somewhere on index.php you could call say:
<?php random_quote(); ?>
“Simple” as that:).

Would you mail it as you post it, or is it an options after the entry is posted?
Either way though, this would be a fairly easy plug-in to write.

Consumer alert: check out these plans first.

CSS Lists

in your stylesheet add:
.meta {
text-align: right;
}
This should work.