Sajda-e-Sahw

Mistakenly reciting a surah instead of attahiyyaat

Q: Is Salaat valid in the following cases? If so, please advise what should be done if such an error occurs in the Salaat.

1. Mistakenly reciting thana twice.

2. Mistakenly reciting some Ayaats of a Surah, or an entire Surah, instead of tashahhud. Tashahhud is then recited after the mistake is  realized.

3. Mistakenly reciting some part of tashahhud, or the entire tashahhud, instead of Surah Fatiha. Surah Fatihah is then recited after the mistake is realized.