check.php an permission checks?

Hello,
thx for your work - Lychee is very nice and I started to use it some weeks ago. In Version 2.1 (rc1 an prior?) die config.php is located in the data directory. Wenn I use the check.php the data directory schould be 0777. I think 0777 isn't the right permission for the data directory or at least the config.php file? Could you please take a look, if this is correct ... maybe I've mixed things. What files will be located in the future under the data directory except config.php? :)