Why isn't an article put front of "whole" here?

What does the pronoun "this" refer to in this context?

Good question. Here, "this" refers to a microphone! It's often said when someone starts speaking when they use a microphone to check that works. Ex: Is this on? Okay, great. Let's start the performance. Ex: Can you check if this mic is on? => mic = microphone

Who does "him" refer to here?

"Him" here is referring to the spider, who he was trying to hit with the crowbar.

What is the word that can be used instead of "naughty" here?

"Naughty" means to be disobedient; badly behaved. Words that can be used instead of "naughty" are bad, rude, defiant, unruly, misbehave. Ex: The children were misbehaving. Ex: He is extremely rude. Ex: Don't be such a bad influence on her.

I've seen the word "sensation" or "sensational" used in magazines before, but not sure what it means. Is there a difference in meaning between "sensation," "sense," and "emotion?"

"Sensational" is an adjective describing something as amazing, impressive, or astonishing. "Sensation" more commonly means a physical feeling or perception in relation to the body. It can also mean that something caused a lot of excitement or interest. As to the difference in words, "sense" and "sensation" are more linked than "emotion," as one can use their "senses," smell, sight, hearing, taste, and touch, to have "sensations," physical feelings in one's body. "Emotions," on the other hand, have less to do with the physical body and more to do with the subconscious! But one could also "sense" someone else's emotions. Ex: I don't like the sensation of eating ice. It's uncomfortable and really cold. Ex: My sense of smell is very good. I can smell food from a mile away. Ex: I can sense that you're feeling upset. What's wrong? Ex: The trip was sensational!

Could you explain the meaning of "make it" here?

"Make it" here means "arrive" or "arrive safely". Here are some examples of "make it" with the same meaning: Ex: Did you make it to the airport? Ex: I barely made it to work on time.