Basic functions needed by our others plugins and templates.
No, are just functions for developers and coders, see k1-functions.php to get more info.
For TIMTHUMB see: http://www.binarymoon.co.uk/2012/03/timthumb-configs/. But, it supposed to work as is now.
Left click on the img, COPY the URL and see the error on the browser, probably you will know what to do.
The FOLDER "cache" must have write access any way.