Is there a command I am missing which allows me to edit the information entered in the Buried Pipe Soil Models after the convert input command has been carried out? I am using Caesar 4.4 at the moment.

No you can't do that, because that information was used to remesh the system and give you the buried model.

If you need to change the soil data, go back to the unburied (original) model. Then re-enter the "Soil Modeler", update the soil data, and recompute/remesh the system.

How does the checker verify that the information used for the soil modeler is correct other than reviewing the print generated during the Convert Input? The convert input report does not seem to be saved in the output report.

You're correct.