[GNC] Car Repair Shop GNU questions

[Martijn Heuts]

Hello,
I just helped a friend with GNUcash (I am a current user as well) however his situation is completely different then mine soI have some questions, maybe you guys can help me?
Question 1:Can I make a summery at the bottom of an invoice with "Total Parts" and "Total Labor"?He itemizes every single 'part' on his invoice and might have 2 or 3 line items of 'labor'.
Question 2:I also noticed the column "Action Items" I can select 'Hours'  or 'materials' or 'Project'.Can I add more items to the "Action Items" column and how can I utilize this in a report?

Question 3:How can I link his bank account to GNUcash?
.Question 4:
Is there any way I can add an extra column when I select "new invoice" for part numbers?
Thanks so much for your help and have a blessed week!
Martijn