Small Biz Sales Tax - Holy Cow!

It works without entering zip codes!
After ignoring this task for several weeks I sat down to tackle this again.  Hours later I reviewed some threads (back a few pages) and changed my set ups.  I tested this by creating multiple new tax groups, customers and orders.
Here are the small biz set ups (all my items are taxable) -
Set up>Set Up Accounting:
Tax Codes Lists = Tax Groups Only
Customers Default to Taxable = Checked
Default Tax Code = Tried to Null out – verbage says “Enter first few letters then tab”
Charge out of district Sales Tax = Checked
Preferred Tax Agency = Null