Set a cooling rack on one side of a grill and heat the grill to high.
To clean the whole squid, grip the squid body, or "mantle," in one hand and the head with the tentacles in the other. Gently pull the head away from the mantle. Most of the innards will stay attached to the head and will be pulled out of the body. Pull out the clear, feather-shaped backbone, or "quill." Cut off the tentacles just above the eyes, remove the pea-shaped peak and innards, and discard. Remove the skin by grabbing with a paper towel and pulling away from the body; discard.
Place the cleaned squid in a mixing bowl with 1 teaspoon of the olive oil, 1 teaspoon of the salt, the pepper, sumac, and cumin. Set aside.
Set the red onion in a large mixing bowl.
Place the squid tentacles on the cooling rack and the tubes directly on the grill grate and grill for 1 1/2 to 2 minutes. Flip and cook for another 1 1/2 minutes. Be careful not to overcook.
Immediately chop the tentacles and tunes into bite-size pieces and add to the bowl of onion. Top with the kale and let rest for 2 minutes. Toss to combine while still warm so the squid helps to slightly wilt the kale.
Add the remaining 1 tablespoon olive oil, the farro, olives, tomato, vinegar, and the remaining 1/2 teaspoon salt and toss to combine. Serve warm or at room temperature.