I love this article but would throw in a few caveats.

I don't think a GSD is necessarily a good fit for someone who has never owned a dog before. They will test the rules and need firm but gentle and consistent handling. They also need a lot of exercise, which you mention, but a lot of people don't know what this entails - I'd say at least an hour a day for them and also goldens and beagles. Two hours for most GSDs and goldens is better.

With beagles - you absolutely cannot let them off leash because, as hounds, if a scent grabs them, they will be off. My GSD, OTOH, has been trained for recall and stays close to me on off leash hikes. I would not do that though with hounds, huskies, etc.

OTOH, beagles are great for fenced in dog parks. GSDs... not so much. Many GSDs can play too rough, though they can be great with dogs they know well... so yes, you are right, socialization is key with this breed, but even with socialization, sometimes they are not good dogs for dog parks. JMHO