We are in a similar situation. The main issue with saving that kind of data is something to do with liability and compliance. If you use Shopify Payments they allow customers to save their cards for reordering. However, I don't know if there is a way...

We use Avalara Avatax for tax calculations. 39 US states are set up, and freight (shipping) is also taxed. However, some Shopify orders do NOT include the tax on shipping, and come up short  on the tax amount. When I contacted Shopify support, they p...