www.wysiwygwebbuilder.com

I am trying to use Breakpoints for the 4 major device screen sizes, 1024,768,460,320. Must I use Flexible layers to place my objects in them or can I use just a normal Grid Layout form? And do I need to set responsive pages for All objects that will be participating in the break point layers?

There are multiple way to make your website mobile friendly. They are documented here:
https://www.wysiwygwebbuilder.com/layout_modes.html

In flexible layouts you can also use easy breakpoints:
https://www.wysiwygwebbuilder.com/easybreakpoints.html