In concurrence that Nature acts as the antagonistic force, it is the huge branch that pinions the men which prohibits their actions. Then, when Ulrich and Georg resove their bitter differences, it would seem that they have conquered their antagonist; however, Nature again fatally defeats them with the appearance of the wolves.
I agree with #4. Both Georg and Ulrich are depicted as being as bad as each other. They have metaphorically become the bloodthirstly wolves that finally devour them. We are given no indication from the text whatsoever that Georg or Ulrich have any points that separate them from the other and distinguish one of them as being a "better" person than the other.
Both Georg and Ulrich are the bad guys. They let their feud turn them into animals with snarling and blood lust. They were turning against their human nature. The animals on the other hand were acting according to nature. Nature was the judge and jury.
The antagonist is generally easier to determine after identifying the protagonist. So who is the main character of this story? One way to tell is to figure out who or what is in conflict with whom or what. Nature is against the two men in the form of a stormy night. Nature is against the men in the form of a fallen tree which traps them. Nature is against the men in the form of hungry wolves. Without those elements there is no story, so we can assume the primary antagonist is nature. Thus, the protagonists have to be Georg and Ulrich--who are also antagonists against each other. So there you have it!
That is a difficult question. The main character of the story, Ulrich von Gradwitz, is not a "good" person. As the story opens, he is looking for his enemy, Georg Znaeym, so he can (apparently) kill him. Znaeym is doing the same. Both characters are "bad guys". In the end, the reader might consider the force of nature as the "bad guy", since both men are made to be helpless victims of nature's power. The wolves could also be considered dark forces, as they evidently intend to kill the men.
6 words: the wolves are the bad guy
i also agree with #4 since both are set out to kill each other. But in the end Ulrich became the bigger person since he decided to end all their hate for each other.