1) The first stage compressor (fan assembly) on a high bypass ratio gas turbine shouldn't penetrate the fan casing otherwise it doesn't get its type approval certificate. Certification tests are carried out during the engine's development stage to ensure this criteria is met. Some engines have high tensile steel casings, others are wrapped with Kevlar.
Countless examples of uncontained engine failures. Just cause it's part of the certification process doesn't mean it can't happen.