http://endnote.com/kb/131728 is a handy document to use to learn how to edit your styles either on Windows or Mac Platforms.
I made the changes you specified (non-superscript citation, (this is citation template, on a PC it is obvious, on a Mac, you need to open the editing tools).
moved year to end in journal template (but that would need ot be done probably for each reference type/template you use) bibliography>templates>ref type you wish to modify,
and changed the authorship criteria to 7 or more, show first 3, et al. (This is under the Bibliography> Author lists)
APA 6th_Ehargreaves.ens (64.7 KB)