Scrub goats are arguable. Being mutts, they can be absolutely superb commercial meat does when bred to a terminal meat sire such as a boer. They are usually hardy, parasite resistant, medium bodied (costs less to feed/maintain and takes up less space than a huge purebred meat animal), and often are prolific. Depending on your resources, pasture management and many other factors, you could possibly sell kids out of scrub does at a bit of a profit just through meat sales. (though not enough to quit your day job, lol). You'd obviously have to cull those that didn't perform, but that's the way it is with every meat operation.
I am not personally against auctions for sending cull animals to market/meat buyers.
Yes, you can allow does to dry up after kidding. With no breeding goals and not milking, I'm not sure why you'd need to breed, though, as it's just more work and you can end up with more on your plate and the animals can suffer from your lack of knowledge, even if you are well meaning.
Personally if it were me, I'd breed with a purpose in mind. I'd cull down to the absolute best, and put some thought into breeding. Management of the animals is your best friend, and it's something that is constantly changing through the seasons. Have you thought about bottle raising or dam raising? Vaccines pre-kidding? Pasture management to reduce worm load? Coccidia prevention/vaccine schedules/dewormer of the kids? Do you disbud or tattoo registerable kids? Do you know how to milk, and how to properly handle milk for safety? Are your goats healthy and disease free? What are you feeding? Do you understand that nutritional needs will change through pregnancy, lactation, growing, and failure in those areas can lead to severe problems? Are you going to be present or able to assist does if they have problems during labor?
Yes, he will breed every doe. And next year, he'll breed every doe again as well as his daughters if they cycle, even if they are too young to handle a pregnancy (Or, their brothers will take care of it if you don't separate them out).