Yes, all of your answers are correct except for number 12. Instead I would say a food chain outlines who eats whom but a food web is all of the food chains in an ecosystem.
Primary consumers are basically herbivores, such as squirrels, rabbits, crickets, etc.
Secondary consumers are carnivores/omnivores, animals that eat other animals such as foxes, snakes, and owls.
Higher order consumers are animals that can eat more things, like humans for example, because we eat animals that are bigger than us like cows but we also eat plants.
Omnivores are animals that eat meat and plants, such as humans and mice because according to your food web, mice also eat meat.
I can’t see the picture very well because it’s blurry, but i think the owl eats some kind of animal that looks like a frog and snakes, so if the owl is removed the frog animal thing and snakes would increase.
for the last question, i would say