In Quik Invoice for Windows or Adagio Invoices, I don't believe there is a 'Prompt for Document Type' option in the Company Profile like there is in Quik Invoice for DOS. It is this setting that allows the user to specify whether an invoice or a credit note is being created.

In newer releases of Adagio Invoices, you can select an invoice in History and restore it to an open batch as a Credit note. This may be an easier way of creating credit notes and avoid what you're running into.

As for the item entry, there are a number of entry setting in the Options under the File menu. If you want to automatically add items with default amounts quickly turn off the 'Edit New Items on Documents' checkbox, and instead select the 'Auto Add Items on Documents'. You can still go back and edit those items for pricing, etc, but when they are initially entered into the invoice, they can be done much quicker.