I am not sure about their policy, but I am also not sure about the idea of uploading the ini file to your root folder.. usually that goes in your PHP folder so when it initializes, the settings from the ini file are used.
Can you find any support documentation at all on their site or with your account. My other concern is that even if a host says they let you control your own ini, many of them have a global ini that can over ride anything you set either way. For example, I can show you how to set your limits simply by putting in htaccess file in your system... but just because the "user level" is set higher won't achieve anything as the "master level"has to also be as high. If you check out your PHP info screen shot, you'll see what I'm talking about - the left column is User Values and the right is Master Values.