Anyone using USPS to ship? Need help quickly! :)

Hi, i'm having a bear of a time with shipping... and i don't know how to resolve... hoping someone has been down this road and can give me some insight.

I've set up USPS and have the API working.
I have the weights for the products.

but.... here's my problems...

1) how do you set the weight for the packaging? if you include it into the product weight, then if a customer orders 2 of that item and it fits in the same packaging, the weight doesn't add up right.

2) say i customer orders ... idk, 2 glasses, the weight is over the first class, so it goes to priority, but on the east coast (where we are) the cost is way lower than on the west coast, so on east coast orders we would ship priority mail and on west coast orders the cheapest would be flat rate. So how do you get it to display the flat rate price in the appropriate size box, just for the places that is more expensive than Priority?

good lord, there's got to be an easier way to figure out shipping!

3) i know PS4.5 doesn't have the ability to print shipping labels, but has anyone found anything that can export the shipping info that can then be imported into the ClickNShip on USPS site?

Thanks for any info/help on this