my problem is solved - maybe it can help
I am still going with my second trial where I renamed the powerstore3 index file to ecart.php and moved everything into the main directory. The primary things to remember is to stay organized so all the new powerstore3 files and folders don't overwrite your files. I have a page template that includes my navigation. In my template, I directed a link to the ecart.php file.
Then here was my fix
change line 58 of the WA_Globals.php file:
Now everything is working OK for me. Hope I helped a little.