1. The only way to fix this is to actually edit the servers php.ini file and change this and restart the server. This is a server thing nothing to be done through the program. The max filesize is not allowed to be set via an ini_set. Here is what can and can not be set program wise through an ini_set PHP: Liste der php.ini-Direktiven - Manual
anything set via system can not be done via a script
2. Well not really with any reliability. The issue is GD2 is part of PHP and as such the white page means PHP is shut down as a result of the problem. There is nothing we can make as far as a message appear because PHP is shut down and we are a PHP script. The server is always first.