Yep these errors are from the web server not eZ, it looks like its not getting to run the index.php.
A good quick test is to replace index.php with your own code to start with, then when you get that working place the eZ one back in place.
If i get this problem i check
Web server with index.htm file
Web server with my own index.php
Web server with eZ index.php with check validity on Web server with eZ index.php with check validity off.
I hope this helps
Tony
Tony Wood : twitter.com/tonywood
Vision with Technology
Experts in eZ Publish consulting & development