The correct answers are: Supposing the chef catches us, what exactly is our escape plan? Assuming we bypass the laser grid, we still have to crack the parmesan safe. Even if we get the recipe, no one will ever believe we pulled this off.

Supposing and assuming are excellent C1-level conjunctions for setting up hypothetical scenarios. Even if correctly introduces a condition that does not change the main clause's outcome.

The sentence starting with Unless is incorrect because "unless" already means "if not," making "unless we don't" a confusing double negative.

The sentence starting with Provided is grammatically correct but logically flawed; we use "provided (that)" for desired conditions or requirements, not for disasters like being attacked by dogs!