No, they're not exactly the same. DC Comics is the original source of the characters and stories, while the DC Universe is a broader platform that includes various media adaptations and related content.
It's hard to say. Goku has his Super Saiyan forms which give him incredible strength and speed. But Flash is known for his super - speed. If it's a short - distance race, Flash might have the edge. However, in a full - on battle where strength also matters, Goku could use his energy blasts and fighting skills to overpower Flash.
Definitely not. The DC Universe app offers a wide range of video content related to DC characters and storylines. In contrast, the DC Comics app is dedicated to providing access to various comic books. They have different features and purposes.