FYI - may help someone down the line
USPS - my regular account (Click & ship) did not work. This left only two options - Shipping Assistant & the API. I wanted to get the real time rates, so wound up clicking on the USPS link from the admin file, and filled out the form. USPS sent an email that has an account number and password which I entered onto the admin section. The email also contained some additional info about testing - I didn't worry about this - just sat tight and in a few minutes another email came through asking for confirmation that you'll be using the API on a transactional basis, and that your output would only be used by USPS. Once you email them back giving them your confirmation and info asked for - the rates & logo come through super.
FedEx - My regular account was strictly online, so all I needed to do to get the real time rates showing, was click on the register button in admin to receive a meter number.
Now both sets of rates are real-time (no problems with shortage), and my insurance rates are also working fine (support corrected an error in the ASP code). So - now I just need to read up to see if I need to anything differently with regard to printing labels with USPS - if anyone wants to add anything, feel free to share!
J-Lynn