I don't think your friend knows what this dog is capable of in terms of its recovery. His genetics might be bad, yes -- but he might be capable of way more than he's presently displaying. I wouldn't want the "bad genetics" label to be an easy out for a person who hasn't at least tried training and confidence-boosting exercises.
"Once abused, always fearful" is a bunch of hooey. Many dogs are resilient in different ways. Some respond brilliantly to an opportunity to build up self-confidence and solid routines but languish without them.
Submissive peeing is easy to manage with GSDs -- I have no idea whether Dalmatians communicate as clearly, but my guess is that they likely do: GSD ear position telegraphs the submissiveness before they pee (the ears are down and back). Once you figure out how to read the ears, when they are in "I'm going to pee" position, ignore the dog! Period. Don't look at it. Don't talk to it. Calmly walk to the back yard and let it follow. Then tell it to go potty. When it does, cheerfully praise the dog for doing the right thing in the right place, and the ears will pop back up and all will be well as the confidence will have returned. Rinse and repeat. Over time, the piddling sometimes becomes less and less when managed this way (at least, that's what happened with my rescue who was a piddler--and we almost never had to clean it up in the house once we learned to read her ears).
As for the rest: I have never yet met a shy, fearful, or shut down rescue that didn't benefit to some degree from a good, basic obedience course. Here's why: their world becomes predictable. They understand what you want them to do, and they're happy to no longer be confused. People suddenly start making sense to them, as you'll be talking the same language. They start to feel good about themselves for always knowing the right thing to do. I've seen several of them go through a transformation in their whole bearing and expression over the course of a good class -- like they're coming alive and finding their self-confidence for the first time. It's a magical thing to see happening in a rescued dog's face and bearing. There is sometimes one special moment, often around week 3-4 in a course, when the head comes up, the shoulders square, the eyes illuminate, and they physically shake off the fearful shadow that had been trailing them. They look at the handler with an expression that says "I'm loving this. This is who I really am!" That's when the spectacular dog in them finally comes out, and the trauma and drama of the past gets left behind. It's almost like the training gives them space to find their true selves.
Maybe this dog has bad genetics. Maybe he's capable of a whole lot more. It's got to be worth trying at least, right?