Therefore I believe that if one was to crease their own website they should use programs such as OScommerce, zen-cart, or openCMS to get all the functionality needed to have a secure and desireable site.
You don't need a shopping cart to have a secure site.
Having a shopping cart like cubecart, oscommerce, etc will definitely help you with the online buying functionality and is recommended.
But it's possible to make a secure site and have people shop and buy at it without having a full on shopping cart.
You could use the tips in the sites mentioned above and add shopping functionality with PayPal, CCNOW, Google Checkout, 2Checkout.com...all places that will do the secure stuff/order processing for you.