Running Balance & Row Auto-Number

Questions
2

This can be done with a pretty simple field renderer check out some of the documentation on that but the idea is something like this:
1) Drag a random number field into the table
2) Set the field renderer as custom 
3) create a javascript snippet like so…

var field = arguments[0],&nbsp; &nbsp; value = arguments[1],<br>&nbsp; &nbsp;$ = skuid.$;<br>var row = field.row;<br>var amountDue = row.Amount_Due__c;<br>var amountReceived = row.Amount_Received__c;<br>value = (amountDue - amountReceived);<br>skuid.ui.fieldRenderers[field.metadata.displaytype][field.mode](field,value);