So I think the issue you are experiencing here is down to how SharePoint presents the data.
When data is stored in SharePoint, there is quite a lot of additional fields created for it in the background and it may be that the field name it gives when you view it in SharePoint list isn't the field name it is stored as.
When you run the activity does it give you the option of providing a CAML query? CAML is the language used by SharePoint to specify what data is retrieved. This can be used to ensure that you only pull back the columns you need
As for the final issue you mention around it returning Microsoft.SharePoint.FieldUserValue
could be to do with it been linked to a person in SharePoint, this isn't a text field. From a programming point of view it contains an object of type Microsoft.SharePoint.FieldUserValue
. If a CAML query can be provided in the activity it may be possible to link the objects together to find out the person name.
EDIT:
I took a close look at the screenshots you attached and you can indeed provide a CAML query to filter the unwanted columns.
As for the person name, looking at similar questions raised on here, and on the SharePoint stackexchange page, I'm not entirely sure if it is possible just using the CAML query.