Those bugs will definitely get you started working with a larger Rust codebase. You might want to at least scan the Rust tutorials on http://www.rust-lang.org/ , though, as just reading Servo code is probably not a good way to initially learn the language. Servo has a lot of foreign function interface code and many parts of the architecture are optimized for performance, making some of the data structures and task communication patterns fairly advanced.
Rust itself also has its own E-easy bugs, many of which are in libraries that do not suffer from the same kind of heavy optimization that we've done in Servo:
