Hi - your mapping looks odd to me in that myFields has been specified as a repeating group. My guess is that InventoryFields is actually your repeating group - you'd want to map using that, then manually add the relative XPaths to your header fields - more like this:
<my:IsRepeating>true</my:IsRepeating>
<my:RepeatingGroup>my:myFields/my:Inventory/my:InventoryFields</my:RepeatingGroup>
-<my:Mapping>
<my:FormField my:IsRichText="false">../../my:Title</my:FormField> <my:SharePointColumn>Title</my:SharePointColumn>
</my:Mapping>
-<my:Mapping>
<my:FormField my:IsRichText="false">../../my:InspectionDate</my:FormField> <my:SharePointColumn>InspectionDate</my:SharePointColumn>
</my:Mapping>
-<my:Mapping>
<my:FormField my:IsRichText="false">my:HazardousMaterial</my:FormField> <my:SharePointColumn>HazardousMaterial</my:SharePointColumn>
</my:Mapping>
Have you added the QdabraRules data source "Error" node to your form to check for qRules errors? Have you verified that other commands work in your form (i.e. to ensure that your custom code + qRules implementation is working correctly) - I like to drag the whole QdabraRules data source onto my form canvas, preview and type "GenerateGuid" into the Command field - do you get a GUID back in the result field?