بسم الله الرحمن الرحيم
الحمد لله رب العالمين والصلاة والسلام على سيدنا محمد أفضل الأنبياء والمرسلين وعلى آله وصحبه ومن تبعه بإحسان إلى يوم الدين
Also who from the maliki school said this?
As for the first hadith, then this is in reference to Abu talib and referring to the uncle as the father is not something unknown, like the "father" of our master Ibraheem alayhisalam. Consider the words of ibnul jawzi
ولوطاً } وهو ابن أخي إِبراهيم، وهو لوط بن هاران بن تارح }
(And Lut) He was the son of the brother of Ibraheem, and he was Lut the son of Haran the son of Terah
[zaad al masir fi ilmul tafsir, commentary under (21:71)]
Hence we can see that according to this the father of our master Ibraheem alayhisalam would be Terah and not Azar, yet the word father is used for Azar. Even if one doesn't accept this view of who was the father of our master Ibraheem alayhislam one can see that father doesn't always refer to the biological father. Due to what has been mentioned, the hadith in Muslim cannot be used as a decisive proof that Abdullah is in the fire, Allah's refuge is sought from such a statement.
As for the second narration then this likewise does not establish that the pure mother of our master صلى الله عليه وسلم was a kaffira, Allah's refuge is sought. As not being given permission to make dua for her doesn't establish that, for had she been as is claimed the best of creation صلى الله عليه وسلم wouldn't have sought permission to make dua for her. The very fact that the messenger of Allah صلى الله عليه وسلم sought permission to make dua for her is a proof that she is in the garden. The prohibition could have just been because, had the prophet صلى الله عليه وسلم made dua for her the people would have followed him and made dua for their parents who died before Islam yet amongst them would be those who died clearly on shirk.
As for those quoted besides Al-Nawawi: as for the text Awn al-Ma’bood then I do not know it nor the state of its author and hence don't consider it, as for bin baz he isn't even someone a donkey would rely upon. As for the words of ibn taymiyyah although I don't care for his words, he was criticising the narrations about bringing them back to life and those narrations being fabricated or not do not establish that they are in hell anyways.
As for killing the one who says "the mother of the messenger of Allah is in hell", then this is because of the intention behind such words, which is to denigrate the best of creation صلى الله عليه وسلم and cause him harm. The position I mentioned was mentioned by shaykh salek who took it back to Qadi abu bakr ibn al arabi.
What one must realise and understand is that, who goes to hell and who doesn't is a point of aqidah hence to establish a certain individual is in hell would require compelling proof. Due to the narrations not being decisive, it is impermissible to use them to establish a point of aqidah. But also one should consider the statement of the messenger of Allah صلى الله عليه وسلم which has been narrated by Bukhari on the authority of Aisha
لاَ تَسُبُّوا الأَمْوَاتَ، فَإِنَّهُمْ قَدْ أَفْضَوْا إِلَى مَا قَدَّمُوا
"Do not abuse the dead, for they have reached the result of what they have done."
And what has been transmitted by Tirmidhi on the authority of Al-Mughirah bin Shu'bah
لاَ تَسُبُّوا الأَمْوَاتَ فَتُؤْذُوا الأَحْيَاءَ
"Do not abuse dead (and) by that harm the living".
And consider the words of Allah
وَٱلَّذِينَ يُؤْذُونَ رَسُولَ ٱللَّهِ لَهُمْ عَذَابٌ أَلِيمٌ
" But those who hurt Allah's Messenger will have a painful torment." [9:61]
So after considering what I have mentioned who will be so bold as to speak ill about the parents of the best of creation صلى الله عليه وسلم ?
This is no joke, this isn't something trivial, no but this is a grand matter with grave consequences. Consider carefully who's parents you are talking about, these are the parents of the best of creation صلى الله عليه وسلم . Reflect carefully on how evil this age is, we have people who become "Muslim" and their fornicating parents die upon kufr and then they start trying to feel good about themselves by mentioning the pure parents of the the best of creation صلى الله عليه وسلم as well as Abu Talib. What kind of a Muslim does this? The believer loves the best of creation صلى الله عليه وسلم more than himself and loves his family more than his own family, no believer is happy about what happened to Abu Talib and no beliver would prefer that his parents be safe over the parents of the best of creation صلى الله عليه وسلم . Fear Allah, establish the prayer and mind your own business instead of asking about the pure parents of the best of creation صلى الله عليه وسلم .
Also reflect upon the words of Allah
وَتَقَلُّبَكَ فِي ٱلسَّاجِدِينَ
And your movement among those who prostrate. [26:219]
Look at how Allah has described the pure linage of the best of creation صلى الله عليه وسلم , yet look at what the people say. Based on inconclusive proof you attack the parents of the best of creation صلى الله عليه وسلم but I bet you're thinking "this aya isn't decisive". Be honest, tell the world that you hate the best of creation صلى الله عليه وسلم and you want to take the people away from him.
Allah knows best, and may He break the backs of those who hate His beloved صلى الله عليه وسلم .