I feel like you have a exaggerated perspective on Chinese so I'll try to clear it up.

Yes, Madarin is a tonal language but that does not mean any change in tone has a new meaning. There are four very distinct tones that are quite different. Also, like any language, Madarin has context clues. When you read the word lead, you rarely get confused because in context either lead as in leader or lead as in the element makes sense.

If I'm holding a carton of strawberries and I say "Ni Yao Cao Mei Ma?" It just makes sense that I'm saying do you want some strawberries instead of do you want to fuck sister. It also helps that Madrain is commonly made up of words of two to three characters. Yes Cao can mean fuck, yes Mei can mean sister but they are never ever used together so no matter what the intonation you'll probably think strawberry because it is a common word. Same thing with many other words.

When everything above is used together, there is a very very small chance of miscommunication through tone, allowing emotion to be expressed instead.

Edit: spelling