Hi Muhamed,
I may be able to help you with the first issue as that isn’t the way the plugin typically works – you may have an issue with your shortcode or specific document. Please use the support tab in GDE Settings to send me the details of the problem and I’ll do my best to help.
The size restriction though is a fact of internet life and a consequence of how Google’s viewer works – I may be able to help you improve this somewhat but not reliably and not by much. It is not within my control.
Thanks,
Kevin