Studies in biology and its effects in our lives are based in evolution. Evolution therefore should not be a battle ground between science and religion. It must be accepted and understood. If we argue over the viability of evolution, we may as well argue over the viability of mathematics because evolution is a quantifiable science.
Biology is a bigger subject that covers more areas that are more important to the human knowledge rather than evolution. Yeah, it's great to trace the ancestry lineage of humans. You are right then when you dig deeper into biology, ti starts to branch. But the fact that biology is the starting place for these several science topics means that everything in biology makes sense rather than only the light of evolution. Evolution does cover a large area, but it's only one of the four main ideas of biology and the other ideas are main because they encompass a plethora of information as well. You are forgetting about biological systems that deal with anabolism/metabolism, communication of organisms that help them aid their chances of survival and reproduction, and the interactions of several systems with their complex properties. These main ideas contribute a whole lot more to humans' understanding of biology rather than only evolution alone. Evolution really is a difficult subject among the other three main ideas because the information keeps changing with more data, but the others are easier to understand since there is less likely to be a major change in a law, theory, or idea in any other three main ideas.
I would argue that Biology is not the starting place for several science topics as physical science forms the basis for biological principles. How does biology describe chemistry or physics? Conversely, physics and chemistry describe factors of biology. You mention metabolic processes as an exemption of evolution, however, metabolic evolution is visible in C4, C3, and CAM plants in which metabolic processes have diverged as a result of their respective environments. Consider also the metabolic pathways between foregut and hindgut digesters and where we find each based on their dietary composition which is reflected by diet quality and efficiency of each type of metabolic pathway. Also, you mention communication and behavior as a mechanism for survival-you are correct. However, communication and behavior is heritable which is a requirement for evolution by natural selection. This also plays into coevolution, as you mentioned complex interactions. Predator and prey systems are constantly evolving antagonistically with each other in order for one to have differential survival, this is a classic example of the Red Queen Hypothesis in which one species is constantly evolving with respect to the other in order to survive- stop and you die. Further, information about evolution does not mecessarily keep changing rather, it is built upon as predictions keep proving to be true, all it would take to buckle evolution is one single fossil out of place and that hasn't happened at all.