Your processor is wrong on one count- home slaughtered meat can be served to "the farmer, the farmer's household, and any non-paying guests and employees". But yes, if you intend to sell pork, it's gotta go through a licensed, inspected USDA processor.
The idea behind these laws is to protect the customer from unhealthy animals processed in dirty conditions. It was too easy for a unscrupulous farmer to chop up a hog mysteriously found dead and sell it, to drop a side of meat in the gutter, to try to "get my money back" from a TB suspect cow that couldn't be shipped.
USDA Processors might not be much better, but at least there's some third parties there- veterinarians who are the meat and livestock inspectors, plant inspectors in the employ of the USDA.
The main disease that hogs would be inspected for is trichinosis, which is almost extinct in US pork.
Unlike milk, meat sold "not for human consumption" has to be MADE not fit- diesel fuel, carbolic acid, and green dye are the suggested seasonings. Yum!
You probably have a custom processor around- the guy that slaughters and processes your animal for you to take home- not to sell. You could sell live pigs or shares of pigs and deliver them to the custom processor (remember, they're not your pigs anymore, you're just transporting them). The people who bought these pigs can then pick them up at the processor-they're picking up meat from pigs they owned.