The ID is sufficient.
You do not need to present a birth certificate to use a passport for its intended purpose. A passport alone is sufficient proof of nationality/citizenship. You may need to present a birth certificate in order to apply for a passport.
NO
Your current passport and your birth certificate are required every time you want to renew your passport.
Nothing but a birth certificate and a passport
No. You require a Passport.
No
The post office does this. You will need your birth certificate.
No you need a passport
birth certificate
Children can get a passport with a birth certificate and parental permission.
You need a certified birth certificate, not a baptismal certificate. It is only important if you have no birth certificate and a letter from the state saying that there is no record after a detailed search of your birth certificate.
Birth certificate, marriage certificate (if applicable), any previous passport issued, photograghs (signed for 1st issue) and the application form signed by an authorised person (UK). Also attend interview (first passport UK), mothers birth certificate.