I can't find, or think of, ANY automated method of Zen Cart installation that can or will be successful in ALL circumstances or venues.

We have a version of Zen Cart that we use for all our customers. It is a current version with all the bug fixes, a custom template, and the few mods that we install on all carts (Encrypted Master Password, Image Handler, UPS, USPS, Fual Slimbox, etc.). BUT, even this is installed using the same method you'll find in the FAQs here or in the docs folder of a standard Zen Cart download.

It's unfortunate that many hosts will include an automated loader from separate sources. There's no way a host can verify all the auto-loaders and (since many have little or no experience with Zen Cart) it "appears" to their customer that a "shortcut" is available. There is none.

And I must point out that one of the questions in the posting tips (Those things that help us to help you) is "HOW did you install it? (upload via FTP and run zc_install, or a one-click install from your hosting company? (one-click installs are NOT recommended))" I wish there were some way to make a poster actually answer the questions in order to post. It would save SO much time for all.

In your case, the time "saved" has cost how much time? Just as there is no "Free Lunch", there is no shortcut to an effective e-commerce solution.

I think you'll find all your problems will go away if you download the files and install them through the recommended method. That way, you'll learn a lot more about the foundation of your store.