Permissibility of reading the night Surahs in Salaah

Asalamualykum…i sometimes find it difficult to read my nightly surahs such as surah mulk etc due to taking care of my baby if i read these surahs in my salaah sometimes will i stil get the reward for reading it nightly such as protection from adhaab of qabr etc or should it be read seperatly?

can i perform salaah with my pyjamas(pants and medium length top) which is not tight fitting with a burqa which comes just above the knee?