With version 1.4, GPix have "Advaced settings" which provide you control over advanced features. You can leave them as is and GPix will work, but you can research them and choose to change for your special case.
GPix have not index_insert.php in distribution, to integrate grid via iframe you can use grid.php
grid code will look like this:
<iframe src ="DOMAIN/PATH_TO_GPIX/grid.php" width="100%" height="1050px" style="border:0; margin:0 auto;"><p>Your browser does not support iframes.</p></iframe>
When users install scripts or play with functionality they can get 'white page'. Commonly page without content mean that something is wrong and you can not see errors, warnings or notices, because reports of this type disabled by php configuration.