"Worf is very handsome."
ghaH is a pronoun. Its primary purpose is to stand in for a noun, and in this way it works just like many English pronouns. Where I can say 'IHqu' wo'rIv "Worf is very handsome," I can substitute in ghaH and say 'IHqu' ghaH "He is very handsome." The ghaH stands in for the noun wo'rIv. When you use a pronoun, you don't use the noun it stands in for.
You can usually drop pronouns where the verb prefix or context makes it clear which pronoun you mean. If you know who the subject of the verb is already, I can drop the ghaH and just say 'IHqu' "He is very handsome." 'IHqu' could also be used to mean "She is very beautiful" or "It is very beautiful," but the point is you already know who is the subject of the sentence, so you can drop the pronoun.
The tips and notes for this topic do a disservice to students. It sort of says what it says in The Klingon Dictionary, which is that leaving in a pronoun where one could theoretically drop it is "emphasis," and many expert Klingon speakers have taken this to mean that 'IHqu' ghaH would mean "He, not somebody else, is very handsome," but really what TKD is trying to get at is that leaving in a droppable pronoun is a way to clarify the subject just in case it needed to be clarified. If I'm talking about a Klingon and a statue, and I say 'IHqu', you might not know whether I'm saying the Klingon is beautiful or the statue is beautiful. If I say 'IHqu' ghaH, you know for sure that I'm talking about the Klingon's beauty. THIS is what it means if you use a pronoun you don't have to.
Another poor choice for the tips and notes is that it introduces the secondary function of pronouns as if it were the primary: pronouns can be linked to nouns to identify them. If I say tlhIngan ghaH, I am linking the noun tlhIngan with the pronoun ghaH, meaning the ghaH is now a substitution for tlhIngan. I can link two nouns with a pronoun, like linking tlhIngan and HoD "captain" to say tlhIngan ghaH HoD'e'. "The captain is a Klingon." When pronouns are used this way, they act a little like verbs in that they can take verb suffixes, but don't think of them as verbs. The tips and notes prompt the student to think of them as verbs, but they are not verbs. They are pronouns that can take verb suffixes when and only when they are performing their "linking" function.
So don't think of ghaH as "he/she is" or jIH as "I am," as the tips and notes suggest. They don't mean these things, and they'll just send you into the trap you fell into. Think of them as pronouns first and foremost, and think of the "to be" sentence as a special formula to follow only for identifying nouns.
ghaH can be used in two ways in Klingon. On is pretending to be a verb in a sentence where are you equating two noun phrases in a "to be" fashion. If we wanted to say, "Worf is a warrior," then we would need to ghaH to act like a verb: SuvwI' ghaH wo'rIv'e'.
The second way is to stand in for a noun that is not expressed, but you want to clarify. If I said that I admired Worf and his gun and then said: 'IHqu'. You might wonder if I was talking about Worf or the gun. So the pronoun ghaH can be used to clarify: 'IHqu' ghaH "He is very handsome." Note, that the verb in this sentence is 'IH and ghaH is acting like a regular old pronoun in this case. However, when we explicitly state the noun in either the object or subject place, we cannot also use a pronoun. Your suggestion "'IHqu' ghaH wo'rIv" winds up sounding like "Worf he is very handsome." In English we either refer to the actual noun or use a pronoun, but not both. Same thing in Klingon (though there is also and additional option of using neither).