Thomas,
1. I simply can’t remove my index.php with htaccess. If I remove it, my site doesn’t work.
We don’t officially support the removal of index.php so I would suggest maybe posting a thread in the CodeShare Corner forum for some community help or trying the Wiki article
2. And every time I saved global configuration, EE tells me my themes-path is wrong. If I change the path in global configuration, nothing happens.
Was your control panel theme not displaying correctly?
What does your path look like?
What is the exact error message you received?
What build of EE are you using as opposed to the version which you already provided