For the second question, yes, for example, you can protect an advanced car engine first, and of course you can also request to protect the car made of this engine in the application for consent. If the engine is creative, the car must be creative, and the two independent claims are also unitary.
Of course, you can also understand the law in this way. If neither of the two ways you say is allowed, there is no need to stipulate the singularity rule in Chapter 6 of Part II of the Review Guide.