Add features in Sales Order

I would like to add the below information to each specific sales order:

1. Freight charge: unlike the built-in “Additional charges and services” section, which is actually reflected in the invoice, we would like to have a separate section to input this freight cost for internal tracing purpose only, and we can only have this info after we booked the shipment with freight company, which is after “Packing" and before authorizing “Shipping”. And having the input info able to be exported to Excel/CSV is desired as well, please help us to solve this request.

2. We would like to have an additional section to input the “Delivered date" (or “Customer received date”) to keep track our service performance. We would like to also export into Excel/CSV in need.

3. Every of our products has a unique serial number for warranty purpose, but we can only know the serial number after the warehouse packed (or even shipped) them. Therefore, the built-in batch/serial No. section in pick/pack is not usable. Please recommend how can we add this info to our order after authorizing Packing/Shipping. We would like to also export into Excel/CSV in need.