So basically the answer is true
The vES ending should be added to nouns that end in -f or -fe in their singular form. In that case, the -f or -fe is removed and -ves is added as a plural ending. Examples include: life - lives, wife - wives, knife - knives, wolf - wolves, leaf - leaves. But there are also exceptions, such as belief - beliefs, cliff - cliffs, roof - roofs.
Completely unrelated, but that is a great sentence, I want that painted as a quote on my wall.
Also, the punctiation seems right to me. But you might be able to use a ";" instead of a comma, im gonna check that real quick.
