Customize Woocommerce Plugin

I purhcased a woocommerce plug in which is used for point of sale system. I need to add more features into the plugin. These are as follows: 1. Add suppliers 2. Add purchase ordering system 3. Product purchasing using Lifo/Fifo techniques 4. Supplier account management, including payments debit/credit. 5. Deposit payment to suppliers for multiple orders 6. Collect payment from customers for multiple orders 7. Customer payments report with debit/credit 8. Supplier payments reports with debit/credit (including collective payments) 9. All products should have expiry field in "add product" section. 10. Addition of shortcut keys in the plugin Point of sale section, for speedy order taking 11. Product purchase price variation, and profit calculation based on variable pricing 12. profit reporting based on variable product pricing