Making a mistake in tashahhud and repeating an aayah of Surah Faatihah in salaah

I have few questions regarding my doubts and sajdah-e-sahw

1. If I performed sajdah e sahw already and then I recited attahiyaat again and committed mistake in the second part of the shahada i.e. (wa ash hadu anna Muhammadan abduhu wa rasooluh) but not corrected and go to durood shareef and while reciting durood remember that I committed mistake in shahada so I just recited the second part of the shahada again and then recited the durood again, is it permissible to recite the mistaken part only or do I have to recite the full shahada again once I reach durood shareef ?

2. If I repeat any ayat of Surah Faatiha, not the full surah or any part of attahiyaat and not the full attahiyaat, does sajda e sahw become wajib or not?