1) Yup, you’ll need to upload the CSS file through here: http://www.tumblr.com/themes/upload_static_file – don’t keep the square brackets.
2) I downloaded your theme, your entire photo post block should look like this if unaltered:
{block:Photo}
Permalink
{LinkOpenTag}
{LinkCloseTag}
{block:RebloggedFrom}Reblogged from {ReblogParentName}
{/block:RebloggedFrom}
{block:Caption}
{Caption}
{/block:Caption}
{/block:Photo}
As you can see, there is no trailling after the link close tag, so I’m not sure what you’re referring to .
Based on the instructions that you showed me above, it should end up looking like this:
{block:Photo}
Permalink
{block:RebloggedFrom}Reblogged from {ReblogParentName}
{/block:RebloggedFrom}
{block:Caption}
{Caption}
{/block:Caption}
{/block:Photo}