Make the sangria: empty 6 Emergen-C sachets into a large pitcher, add 6 cups water and stir until dissolved.
Add 1½ cups pineapple juice and ½ cup pomegranate juice to the pitcher and stir to combine.
Add the prepared fruit (apples, blackberries, raspberries, kiwi, tangerine segments, pomegranate seeds, and grapes) to the pitcher and gently stir; chill or serve immediately with a rosemary sprig if desired.
Prepare the salmon: preheat the broiler to high and line a baking sheet with foil.
Toss 1.5 lb cubed salmon with ½ tsp kosher salt, ½ tsp black pepper, 1 tsp oregano, juice of 1 clementine, 1 tsp garlic powder, and 1 tbsp olive oil until evenly coated.
Arrange the salmon cubes on the prepared baking sheet and broil for about 8 minutes, until cooked through and slightly browned; remove and let cool a few minutes.
Skewer each salmon cube with a toothpick and top with a broccoli floret to make bites; serve immediately or with the sauce.
Make the sauce: whisk 2 tbsp sangria (no fruit), 1 tsp oregano, ¼ tsp salt, and ¼ cup olive oil in a bowl until combined; drizzle over salmon bites or serve on the side.