Checkout workflow questions

Please respond to the following issues/questions about the checkout process:
(I am using the Authorize.net payment plugin)

1)I was able to submit and process an order by providing only my credit card number and expiration date. I did not input any shipping address or billing address information and no error message appeared to indicate that that was necessary.
How can I make the shipping address and billing address fields required?

2)In the Authorize.net settings, I have selected "Yes" for Card Validation Code but in the checkout process, no window appeared that would allow me to enter this code.
How can I require it and show a window to enter this information?

3)A transaction summary page did not appear.
Prior to submitting the transaction, how can I show the customer a page that summarizes all of the purchase information such as product purchased, price, shipping and billing information, credit card number, etc.?

4)I have set up different tax zones, tax rates and tax rules for different states such as California and New York. Will the tax be applied after the shipping information is inserted? Will it appear on the transaction summary page?

5)Here is a screen capture of my checkout workflow window:

This is great...thanks very much Nicolas!

A few more questions please:

1)My client would prefer that his customers not be required to log in which is why I removed the login_address_part of the checkout workflow.
When I made a test purchase earlier today without the login screen, the address interface was displayed but the address fields were not required.
How can I make the shipping address and billing address fields required without making the customer login?

2)I need the tax to be applied and displayed on the very next screen after the customer inputs the address information but before the transaction is submitted for processing to the bank.
How can I display a transaction summary page with the applied tax and shipping before the transaction is submitted for processing?

Thanks Nicolas.
I'll work with this some more and get back to you with any questions.
I plan to buy the commercial version for this client in the coming weeks.
Must I uninstall the Starter before installing the commercial version or will the Starter be over-written by the new installation?

Thanks.

I am not able to get the tax function to work for any of my products.
I have created some tax zones, categories, rates and rules and have set the tax category in each product information window.

Thank you.

I checked all my tax-related settings against the tax FAQ information and everything looks correct. Please answer these additional questions that may help me to get the tax function working:

1)When creating a tax rate, what should we input for the "Tax namekey"?
Should the "Tax namekey" be the tax zone name, tax zone name in English, code 2 letters or code 3 letters?

2)When we create a tax zone with subzones, must we also create a tax category for each subzone?

OK, I got the tax function working...thanks for all your help!
I have one final problem:
When I view the products on my web pages, the products show prices that include the tax.
How can I display the product prices without the tax?

That's great...thanks!