Hot zone. Air lock. These are both examples of jargon, aka slang.
D. third person voice and present tense verbs.
You use 3rd person because it is more formal. The teacher always says "don't use I!"
You use present tense to talk about the book because even though you as the writer already read the book, the person who is reading your analysis may not have read the book, so use present tense. For example, you should write, "The book states on page" instead of "The book stated on page"
He's hoping to convey the differences and similarities of the German government from governments of the past since that is the purpose of making comparisons. This is for a better understanding of the successes and failures of the German government.