Black staining would be extrinstic ...Will go after professional oral prophylaxis (scaling and polishing).
For the other two problems plz seek consultation with an orthodontist...it problems would be permanently solved after taking orthodontic treatment.
Next Steps
search for an Orthodontist I.e. an doctor with the qualification of MDS Orthodontics
Health Tips
avoid any iron syrups as they can cause black stains on teeth...u can ask for iron tablets instead...if u r on any iron medications.