Of course ZenCart can be used to build an entire website that is an eCommerce store, but can ZenCart be used on an existing site, sort of as a "module?"
Let's say I currently have a website, and I have decided to sell some products (add eCommerce functionality), but I want to keep the look and feel (CSS and general layout) of the original site. Is ZenCart a good fit for this purpose? I have seen some websites that have a completely different look and feel when the site visitor goes into the eCommerce portion of a site. I don't want that.
My questions:
The answer to question 1 is no. The answer to question 3 is Foxycart or Paypal.