Every argument must have a conclusion. An argument must have a point that is being made, though that point might be implicit. All cogent arguments are sound arguments. Sound arguments meet the R and G conditions by being deductively valid. A cogent inductive argument would not be sound.
All cogent arguments are valid arguments.
Deductively valid arguments are not inductively strong so a cogent argument that was inductively strong would not be valid. If the premises of an argument are false, the argument is invalid. A vague word has two or more definitions. For example, 'tall' doesn't have more than one definition, it is just that the definition is not precise enough to serve in an argument. An ambiguous word has two or more definitions.