Hi,

Maybe shipping configuration would be easier if there's only one module that
manages :
- Price based shipping costs
- Weight based shipping costs
- Destination based shipping costs

Then, it would be possible to calculate shipping with various rules depending on
price / weight / destination of the order.
The E-commerce software Prestashop is using such a system, and I think it's very
easy to use

Maybe I can help for such a project ?