What is confusing me is the interaction between modules and templates with php code.
In zencart modules I see php/mysql code but no echo statements.
There are functional files that retreive the data and the template files 'tpl' that describe how this is to be displayed.

You can work around this if you wish but realize that in some cases you will lose the ability to control from the admin and or the dynamic nature of the cart. Or as it can be termed this will end up being hard code.