Default Theme Won’t Load

I’ve been on a downward spiral all night… First, I had a problem getting my personalized theme to load after I had installed the Photopress plugin… https://www.ads-software.com/support/topic.php?id=25727
In an effort to solve that problem, I tried my best to uninstall the plugin, but all of my the program won’t seem to completely uninstall and my original theme simply won’t load.

I then switched over to using the default theme and I made some adjustments to the style.css file to match the previous color scheme of the site. Then the default theme crashed as well. Despite deleting the default theme and reloading it (multiple times) to my server, I get this error at the top of the admin screen under the “presentation” tab. (I’ve checked that I’m using all the “default” files that came with the initial download of WP 1.5). Any idea what would cause error?

Where would I look to find a problem with this theme that runs deeper than the files within the “default” folder?

Warning: file(/home/rainci5/public_html/wp-content/themes/default/style.css): failed to open stream: Permission denied in /home/rainci5/public_html/wp-includes/functions.php on line 1324

Warning: implode(): Bad arguments. in /home/rainci5/public_html/wp-includes/functions.php on line 1324

Warning: Cannot modify header information – headers already sent by (output started at /home/rainci5/public_html/wp-includes/functions.php:1324) in /home/rainci5/public_html/wp-admin/themes.php on line 18

Thanks in advance! Any help will definitely be appreciated and hopefully allow me to turn this weekend around!