Re: the use of the pronoun "it" in specific sentences
Custom plays a role here, monetina87.
Sentences like this one are common: I love what you've done with your hair. = I love your new hairstyle.
Sentences like this one are unusual: I love when you give me money??? People generally prefer to use "it" in this and similar sentences that use some clause beginning with "when": I love it when you give me money.
Cross-posting yet again.
...It is a tale told by an idiot, full of sound and fury, signifying nothing. W. Shakespeare