Unknown, it's physically possible to have a population with internal variation and replication while ensuring that it doesn't fall into certain destructive patterns with specialized controls. This is probably not a particularly good example since afaik multicellular organisms don't normally have much variation in their genetic code, but one of the methods for "outlawing evolution" (as mentioned by Eliezer) in multicellular organisms is Macrophages attacking tumor cells. It's not perfect, of course; individuals still die from cancer. But that mechanism is something produced by natural selection; an intelligent designer could do much better. You haven't yet convincingly argued that variation and replication necessarily lead to destructive runaway effects; you might need controls (which natrual selection may never come up with) to prevent it, but that doesn't make it impossible.