Hello,
Sorry if I'm asking questions you know right away but I don't. I'm definitely no programer, so I'm just trying to make sure if I make a change I don't screw something else up
You're totally right to ask questions if things don't go the way you want !
#1 The problem that we are having now it probably that the package calculation algorithm of the USPS shipping plugin is automatically and efficiently "grouping" products with each other until the USPS limitation is reached, so USPS shipping rates will automatically be cheaper.
#3 By doing the code customization that I gave you, it will automatically send 1 product per packages so USPS rates will be more expensive.
Also are you having that issue when you only have one product on your cart ?