As a Westerner who learned Chinese after reaching adulthood, I might be able to clear up some of these arguments, at least from my perspective.
Characters are largely memorized by components, though components only rarely give useful hints as to the meaning or pronunciation of the character. For example, if a character has the component for "gold" in it, you are never going to be able to guess what it means, because that information is just not specific enough. If you are trying to remember which radical goes on the word for "coin," though, "gold" is a safe bet. So the hints of meaning are utterly useless for deriving meaning from characters, but are fairly useful for helping you remember how to write characters.
As for pronunciation, you will rarely guess the correct pronunciation of a character if you haven't seen it before and don't happen to understand the context. For example, if a character is made of a component that is pronounced "ji", there are just too many possibilities to allow you to guess the new character's pronunciation ...
- It might be pronounced ji
- It might just rhyme with ji (xi, qi, bi, li, ti, pi, etc.)
- It might start with a similar consonant sound as ji (ju, zhu, zhao, etc.)
- Or it might just be pronounced completely differently, though this is probably true in the minority of cases
Again you can see how these clues might help you remember how to write a word you know, because you can recall a similar meaning component and a similar pronunciation component in lots of cases, but you can rarely use these clues to figure out the meaning or pronunciation of a character in isolation.
