USPS Web Tools & Zen Cart

I would like to use the USPS webtools on my cart but I am confused by several things...

Do I still need to "test" the URL's with XML as suggested in the e-mail I recieved, and then e-mail usps when the testing is complete, or can I just set up my USPS module on my cart and switch to the production server instead of test?

I guess I don' tknow of ZC will do all of the configuring automatically? I know nothing about xml and how i need to do the URL testing, I did download the admin guide from the usps website but I don't know if it applies to me, or like I said if zc automatically gets it going for me?

Then about packaging ratios - if I ship mainly in large envelopes or small cardboard boxes, how would I figure how much weight these things would add? I'm so confused with this.

First time zenner here... lol. thanks in advance.

I integrated USPS webtools, but the test mode in ZC did nothing. So I just notified USPS to put my account into production, switched ZC to production mode, and every thing worked fine. As far as the packaging ratios, I have yet to see a reasonable explanation in these forums as how they are supposed to work. Still searching for an answer of how to deal with oversize packaging.

Good Luck.