Qiraat in Salaah

Reciting the first 3 verses only of Surah Faatiha in every rakaah of salaah

Q: As we know it is waajib to recite the first 3 verses of Surah Faatiha in every rakaah of salaah.

I heard a mufti say that qiraat changes the amount of verses in the Quraan. If I recite the first three verses of Surah Faatiha and combine the second and third verse and not recite further would my prayer be valid?

Obtaining the virtue of reciting Surah Sajdah and Surah Dahr in the Fajr Salaah on a Friday

Q: With regards to Friday Fajr salaah: If I read Surah Sajdah in 2 rakaats one week, and the next week read Surah Dahr in 2 rakaats, will I get the fadheelat of the sunnah? Because the musallees are old, and they do not like to read long salaah. For this reason, can I get the reward for the sunnah?

If there's no sunnah reward for this, then how can I get the sunnah reward?