Is it permissible to recite Ayat al-Kursi after the surah in the first rak'ah of prayer, and to recite two surahs after Al-Fatiha in the second rak'ah?

It is permissible for the worshipper to recite Ayatul-Kursi, Surat Al-Ikhlas, or other surahs after Al-Fatiha along with another surah. It has been authentically reported from Aisha (may Allah be pleased with her) that the Prophet (peace be upon him) approved of a Companion who used to conclude his prayer with "Qul Huwa Allahu Ahad" (Surat Al-Ikhlas). This action is permissible, but it is not a regular Sunnah from the Prophet (peace be upon him). It should not be continuously observed in every prayer so that it does not become a Sunnah. Sheikh Ibn Baz issued a fatwa permitting the recitation of more than one surah after Al-Fatiha in a single rak'ah, and that there is no harm in that, even if it contradicts the order of the Mushaf, although it is preferable to maintain the order as in the Mushaf.