Hi Ken, I'd have to research why the button is not there, separately, I assume it is by design, though.
I don't ever ever use the Save and Save As buttons in my forms, though. Here's what I typically do in order to achieve what you're trying to accomplish:
Create a field in your form's data source called "FormStatus". The default value can be "Draft". Another value you'll be using is "submitted". Instead of setting the fields as required, set up a validation rule on each field where it is required only if Status is equal to Submitted. Then, put two different buttons at the bottom of the form. "Save Draft" or "Submit Final". When they click Save Draft, the action will be to submit it using a data connection, but they won't get the validation errors because status is not equal to Submitted. When they click "Submit final", the first action is to set the FormStatus field to "Submitted", and then submit it via the same data connection. This way, when they click to submit final, it will then give them a validation error for any missing fields. In the form library, you can create a view caled "My Drafts", where Created By is equal to [me] and FormStatus is equal to Draft.