I wanted to get verification on the consequences of making a change to a customized work item.  I was trying to change my field 'Customer Name' to 'Customer Profile'.  I thought perhaps I could edit field name 'customer name' to 'customer profile' using the same 'customerName' id I had originally created.  I could not seem to do that, so I assume that is how RTC works.  Instead, I ended up creating a field 'customer profile' and noticed that I can see the new field 'customer profile' in any new work item I open, but the effect on existing work items is that the 'Customer name' has disappeared from the existing work items.  
    So, I was wondering if I edit the editor presentation and put the field 'Customer Name' back in, will it show up in the existing work items where that field once was? (or has that ship sailed?)  The existing 'Customer Name' field had plenty of capacity to do what we wanted to do (include a customer profile in the record that we can run a query on), but the team wanted the field name to be representative of the contents.
    Also, we would like to get rid of the test records and we are unable to delete them.  I understand that RCS does not allow that with our RTC instance.  It was suggested setting up a team area, and associating those records with that team area.  Looks like that would work only if I had not deleted the 'Filed against' field.  So, I am wondering if I would be able to add that field back in, and if I do, will it appear in the existing work items.
Thank you.