I don't think there are any OSS/FLOSS licenses that have non-commercial clauses, so CC NC is the best you can get among popular licenses.
When you use dependencies, your project (its users) must comply with all of the licenses together. IANAL, but I think CC and MIT (and other similarly permissive) licenses are compatible — you'll need to include text of the permissive licenses to comply, and that's not against CC.
If you take contributions, be clear what license they give you.
People can have various reasons for such look. It can be a symbol of non-conformity.
Official Rust spaces have a code of conduct that is inclusive and forbids discrimination, and this may attract people who otherwise wouldn’t feel comfortable to participate.