Well, you can't really find an exact English equivalent for a lot of Japanese characters, especially particles. Even the sentence structure is vastly different, and will serve to confuse if you seek to find the exact English translation, word for word, or character for character.

As for the pronunciation, you can't really blame the rest of the English speaking world. It's how they have been taught to read, because they don't see the Japanese text as broken up into Hiragana characters but a whole word in its entirety.

Furigana is the little hiragana text you see on top of kanji. It's used in complex kanji, or in cases where the pronunciation of the kanji is different/special. It also helps people to learn kanji too, since there are so many kanji with different meanings and pronunciations.

I'm preparing for my level 2 exams this year.