What are the best chmods for all files and directories after installation?
The ones that you changed for the installation need to be set to what you changed them to, everything else can be 644 for files and 755 for folders. You can set ./inc/config.php to 444 if you want to.
As I said, things that needed special CHMOD settings for the installation need to keep those settings, which includes settings.php - config.php is the exception.