Salam alaikum.

In his book “Biharul anwar” (8/365) Majlisi narrated:

وقال النبي صلى الله عليه وآله : من جحد عليا إمامته من بعدى فإنما جحد نبوتي ، ومن جحد نبوتي فقد جحدالله ربوبيته .

“Prophet (sallalahu alaihi wa alihi) said: “Whoever would reject imamate of Ali after me, he rejected my prophethood, and whoever rejected my prophethood like rejected Allah and his lordship”.

And in the same volume at page 366, he narrated:

و قال النبي صلى الله عليه وآله : الائمة من بعدي اثنا عشر أو لهم أميرالمؤمنين علي بن أبي طالب عليه السلام وآخرهم القائم ، طاعتهم طاعتي ، ومعصيتهم معصيتي ، من أنكر واحدا منهم فقد أنكرني .

And prophet (sallalahu alaihi wa alihi) said: “After me would be 12 imams, first of them commander of faithful Ali ibn Abu Talib (alaihi salam) and last from them is Qaem. Obedience to them is obedience to me. And disobedience of them is disobedience to me, and whoever would reject one of them, he rejected me”.

And at the same page he narrated:

وقال الصادق عليه السلام : من شك في كفر أعدائنا والظالمين لنا فهو كافر .

And Sadiq (alaihi salam) said: “Whoever would doubt in disbelief of our enemies and our oppressors is kaafir”.

And at page 368 he quoted other shia scholar, sheikh at-Toose:

عندنا أن من حارب أميرالمؤمنين كافر ، والدليل على ذلك إجماع الفرقة المحققة لامامية على ذلك ، و إجماعهم حجة ، وأيضا فنحن نعلم أن من حاربه كان منكرا لامامته’

And in our view whoever fought against amiralmuminin he’s kaafir, and proof for that is agreed opinion of firqatu al-muhaqaqat al-imamiyah, and their agreed opinion is a proof (hujja), and we also know that whoever fought him, he rejected his imamate…

Conclusion:

1) All Muslims who rejected imamate of anyone from 12 imams are kuffar in the view of imamiyah.

2) Aisha, Talha, Zubayr, Muawiya are disbelievers in accordance to agreed opinion of imamiyah.