Edit the "Quick Create Form" for Phone call entity & not mark the phone call activity automatically completed for CRM 2013

Hi,

I see that the phone call quick create form is managed and customizable=False in CRM 2013. Is there any way we can make it customizable=True and edit the form? probably via xml change?

Also, is there anyway to make the phone calls NOT automatically completed when created from activity feed? Thanks for your help and suggestions!