First of all, the configuration setting you're using is for item options. These are things that user selects to tailor their product selection: colour, size, etc. These are typically tied to matrix children or to custom transaction line fields or item options. So, in short, this is not the correct place to put those.
Secondly, how is expected ship date calculated? When is it calculated? Is it dynamic based on the users details (eg their location)? Etc. If so, you are talking about a reasonably complex customisation because this is not a static field on the item record, but rather than that is dynamically generated on the fly based on user selection.