Using 'no' for nouns can make the sentence sound unnatural and may lead to confusion. For example, instead of saying '彼は日本に5年も住んでいる。日本語がうまいわけだ。' (He has been living in Japan for five years. It means he's good at Japanese.), you could say '彼は日本に5年も住んでいる。日本語がうまいというわけだ。' (He has been living in Japan for five years. It means he's good at Japanese.).

While both 'hazu da' and 'wake da' can be used to indicate that something is the case, they have different connotations. 'Hazu da' implies that something is expected or predicted, while 'wake da' implies that something is the case and provides a reason or explanation for it. For example, instead of saying '彼は日本に5年も住んでいる。日本語がうまいはずだ。' (He has been living in Japan for five years. He's expected to be good at Japanese.), you could say '彼は日本に5年も住んでいる。日本語がうまいわけだ。' (He has been living in Japan for five years. It means he's good at Japanese.).

While 'because' can be used to indicate that something is the case and provides a reason or explanation for it, 'wake da' has a more nuanced meaning. 'Wake da' implies that something is the case and provides a reason or explanation for it, while 'because' is a more general term that can be used in a variety of situations. For example, instead of saying '彼は日本に5年も住んでいる。日本語がうまいからだ。' (He has been living in Japan for five years. Because he's good at Japanese.), you could say '彼は日本に5年も住んでいる。日本語がうまいわけだ。' (He has been living in Japan for five years. It means he's good at Japanese.).