Bring 4 quarts water and 2 teaspoons salt to a boil in a 5-quart pot. Add wild rice and simmer, partially covered, until rice is tender and grains are split open, 1 to 1 1/4 hours. Drain rice well in a large sieve or colander. Meanwhile, cook snap peas in a 4-quart saucepan of salted boiling water until crisp-tender, about 2 minutes, then transfer with a slotted spoon to a bowl of ice and cold water to stop cooking. Drain peas, then pat dry between paper towels and cut each pod diagonally in half. Whisk together vinegar, mustard, sugar, and remaining 3/4 teaspoon salt in a bowl, then add oil in a slow stream, whisking until combined well. Whisk in dill. Combine peas, salmon, scallions, and eggs with warm rice in a large bowl. Drizzle with dressing and toss gently. Serve warm or at room temperature.