Answers

1. Our docstrings can support Markdown while we are building our structs and functions. Because it's Markdown, we can document ways in which we can implement the struct or function. If we are using Visual Studio Code, this also helps our productivity, as merely hovering the mouse over the function or struct throws up the documentation.
2. Keeping our modules constrained to a single concept increases the flexibility of the application, enabling us to chop and change modules as and when they are needed.
3. In order to keep our modules isolated, we need to keep the interfaces of the module the same; this means that we can change logic inside the module without having to alter anything in the rest of the application. If we delete the module, we only have to look for implementations of the interface throughout the application as opposed to the implementation of all functions and structs in the module.
4. We manage our dependencies in the Cargo.toml file. Just running Cargo...