The template issue is one that happens from time to time. Attaching the template after the fact should not cause any problems, you will just need to match up the regions of the page with the editable regions of the template.
The error you are getting on this page is just letting you know that the variable being referenced has not been defined and does not have a value. When you are testing this have you ensured that you have all of the files uploaded? You may want to check this page to see if there is a missing include for the USPS files, you should have them on the page that returns the quote.
Entering a whole number or decimal value should be fine, do you have problems with one of these?
With PayPal standard the shipping quote should be fine to pass as the shipping and handling value.