Sales tax for customers

Sales tax for customers

In Europe according to the type of client, sales tax is not always due. Would it be possible at the customer level to tell what type of tax is to be applied. This could then be used in conjunction with the product tax when quoting or invoicing.

More generally, would it be possible to set up forms which allow
- conditional calculations on fields
- allow to combine fields of different components (eg. products, price books, invoices and accounts)
Thx