wa ʿalaikum al-salām wa raḥmatullāhi wa barakātuh
Khulʿ is a type of divorce, therefore, the waiting period [ar:ʿidda] in a khulʿ is the same as that in an ordinary divorce: If the woman still gets her menses, then her ʿidda is three purities; and if she no longer gets her menses, then her ʿidda is three Hijri lunar months.
As for the financial upkeep [ar:nafaqa], she is only eligible for housing provided that she was not nāshiza during the time of Khulʿ and/or anytime afterwards. Finally, she is also eligible for mutʿa regardless of whether or not she is nāshiza.
Allah knows best.
Answered by Shaykh Omar Mohsin