Spreadshirt Shop Commission help?

I have a shop on Spreadshirt and I have 2 problems with multiple questions. Problem 1: Question 1. What is the difference between "Design commission" and "Shop-Product commission"? Question 2. Which commission option is the one that earns me money? For awhile I had them both set at $5.00 for all of my products and I was making around 1-2 sales per month but every time I would check my Spreadshirt finances, I would only be getting $5 per product sold. Problem 2: Question 1. How do I transfer my finances over to my Paypal? Question 2: If I use my bank information instead of Paypal, would I have to notify my bank? I have my Paypal account linked up to my Spreadshirt account but whenever I check my bank account or my Paypal, There is no monthly commission from my Spreadshirt shop. Please help!