I have similar views as yours ... no cutting, no bending is the rule for me!!!
The installer would surely insist on putting the speakers on the top .. but you are the customer, and the customer is always right .. if he follows your instructions, fine, otherwise you should find another installer.
So far, I have not let anyone do any cutting or bending in my Laadli ... The only close thing was that rivets had to be opened to uninstall the front door speakers in order to install the Pioneer components.