Place beans and cumin in a small bowl; partially mash. Season to taste with salt and pepper. Mix 2 teaspoons olive oil and lime juice in a medium bowl; add coleslaw, green onions, and cilantro and toss to coat. Season slaw to taste with salt and pepper.

Heat 1 tablespoon olive oil in a large nonstick or cast iron skillet over medium-high heat. Add tortillas in a single layer. Spoon 1/4 of the bean mixture onto half of each tortilla; warm for 1 minute. Fold tacos in half over filling. Cook until golden brown underneath, about 1 more minute, then flip and crisp on the second side, another 1 to 2 minutes. Spoon feta and slaw into tacos. Pass hot sauce alongside.