The land itself does not produce wealth, but wealth is produced when people conduct economic activities, such as production and sales, on it (literally: by (people's) conducting economic activities such as production and sales on it).
(g).
お年寄りを狙い、強引な方法で家屋の修理契約を結ぶ手口は卑劣そのものだ。
(literally: Their way of) Aiming at the elderly and forcing them to sign a house repair contract is utterly contemptible.
(h).
そのマニュアルは説明も図も明快そのもので、画像処理の知識がない者にもよく分かる。
The manual's explanations and figures are perfectly clear, so even people with no knowledge of image processing will be able to understand them well.
(i).
米倉さんは誠実そのものの人柄で知られている。
Ms. Yonekura is known for his totally sincere personality.