The Belief regarding the 12 Imams

Assalaamu-alaikum,

I wanted to know what is the belief of us Salafis regarding the 12 Imams mentioned by the Shia? For example, with exception of Ali bin Abi Taalib (Radhi-Allah Anh) and his two sons Hassan and Hussein (Radhi-Allah Anhum) of whom we know of their high status, but what do we know of or hold in belief regarding the likes of:

Please Note: The bracketed names are titles given to them by the Shia I think, but please rectify me if I am wrong.

Ali ibn Husayn (Zaynul Aabideen)
Muhammad ibn Ali (Baqir al-Ulum)
Ja'far ibn Muhammad (As-Saadiq)
Musa ibn Ja'far (Al-Kadhim)
Ali ibn Musa (Ar-Rida)
Muhammad ibn Ali (Al-Jawad)
Ali ibn Muhammad (Al-Naqi)
Hasan ibn Ali (Al-Askari)
Muhammad ibn Hassan (Al-Mahdi)

The last one obviously we don't know because the Mahdi hasn't arrived yet so we won't know anything regarding that. I remember reading an article on one of our sites where I think Shaikh Bin Baz (Rahimullah) explains the hadeeth of the 12 leaders of Quraish which made perfect sense. However, little is known to us about these individuals (myself especially), did all of them really exist or is it just another Shia deception and delusion? I have tried looking through Islamic history books and the internet but there's very little info on some and no info on many others. Any info that is available is written from the Shia perspective, which undoubtedly is baatil. If anyone can provide detailed info, it will be much appreciated, or if it is a matter I should not read about as it is of little importance, then please say so and I will leave it. Jazakallah khair.

Wassalaamu Alaikum Warahmatullahi Wabarakatuh

Ibn Taymiyyah divides the 12 Imams of the twelver shi'ah into four groups.
The first: Those who were noble companions of the Messenger sallallaahu alaihi wa 'ala aalih. These are 'Ali ibn Abee Taalib and his two sons Al-Hasan and Al-husain radiyallaahu 'anhumaa
The second group: which consists of noble scholars these are Ali ibn Al-Husain, Muhammad ibn Ali Al-Baaqir, Ja'far Al-Saadiq and Musa ibn Ja'far radiyallaahu 'anhum who are all trustworthy scholars. (Al-'ulamaa al-thiqaat)
The third Group: this group includes Ali ibn Musa, Muhammad ibn 'Ali al-jawwaad, 'Ali ibn Muhammad Al-'Askari and Al-hasan ibn 'ali al-'askar. iIbn Taymiyyah states about them: " There was not known among them those who were known for knowledge that would benefit the ummah, nor for having a hand by way of which to benefit the ummah, rather they were like their peers from the hashimites, having respect and nobility, and knowledge by which they could fulfill what they were in need of which is what many of the common muslims have but as for the level of knowledge on a scholarly level then this was not known of them and due to this the scholars did no take from them as they took from the previous three.
As for the fourth group: this includes the hidden Imam Muhammad ibn Al-hasan Al-'Askari then that which is most correct is that he never existed and Allah knows best
ويُقّسِّم ابن تيمية رحمه الله الأئمة الاثنى عشر إلى أربعة أقسام:
القسم الأول: علي بن أبي طالب ، والحسن ، والحسين رضي الله عنهم وهم صحابة أجلاء، لا يُشَكّ في فضلهم وإمامتهم، ولكن شَاركَهُم في فضل الصحبة خلق كثير، وفي الصحابة من هو أفضل منهم بأدلة صحيحة عن النبي صلى الله عليه وسلم .
القسم الثاني: علي بن الحسين ، ومحمد بن علي الباقر ، وجعفر بن محمد الصادق ، وموسى بن جعفر، وهؤلاء من العلماء الثقات المعتد بهم . منهاج السنة : (2/243،244).
القسم الثالث: علي بن موسى الرضا، ومحمد بن علي بن موسى الجواد، وعلي بن محمد بن علي العسكري، والحسن بن علي بن محمد العسكري ، وهؤلاء يقول عنهم شيخ الإسلام : " فهؤلاء لم يظهر عليهم علمٌ تستفيده الأمة، ولا كان لهم يدٌ تستعين بها الأمة، بل كانوا كأمثالهم من الهاشميين، لهم حرمة ومكانة، وفيهم من معرفة ما يحتاجون إليه في الإسلام والدين ما في أمثالهم، وهو ما يعرفه كثير من عوام المسلمين، وأما ما يختص به أهل العلم، فهذا لم يُعرف عنهم، ولهذا: لم يأخذ عنهم أهل العلم كما أخذوا عن أولئك الثلاثة، ولو وجدوا ما يُستفاد لأخذوا، ولكن طالب العلم يعرف مقصوده " منهاج السنة (6/387).
القسم الرابع: محمد بن الحسن العسكري المنتظر ، وهذا لا وجود له .
والله أعلم .