The hadeeth you are quoting are weak on their own . Not hasan .
SubhanAllah. The scholars of hadith have explicitly said the
chains are Hasan. Al-Albani, Arnaut, and many others. Maybe you would prefer the grading of non-scholars on an online forum, and so let me show you what TSN themselves have said regarding the first tradition, where they grade it as Hasan themselves, according to what they deem orthodox standards of Rijal.
From TSN itself:
http://twelvershia.net/wp-content/uploads/2013/10/List-of-Texts-and-Chains-of-Thaqalayn.pdf"Sulayman bin `Ubaydullah al-`Aylani -> abu `Amir -> Kathir bin Zayd -> Muhammad bin `Umar bin `Ali -> his father -> `Ali bin abi Talib.
Hasan, Sulayman is Saduq, `Abdul-Malik is abu `Amro and he is Thiqah, Katheer bin Zayd is Saduq, Muhammad is `Ali bin abi Talib's grandson andIbn Hajar said Saduq in al-Taqreeb, Majhool according to Shia, `Umar is `Ali's son and he is Thiqah..."
Many scholars have graded the chain to be at least Hasan not because they are being lax, but because he chain meets the criteria of a Hasan hadith. You can play this game of Jarh' and T'adil and weaken how you see fit, but it will go against many far more knowledgable scholars of Hadith.
Secondly, the text of the report is faulty. And no matter how many they are if they go against the authentic version , supported by external reports as well , then they are classed as Munkar.
SubhanAllah, the reality is, the Hasan chains are not 'Munkar', nor do they go against what Zayd has narrated or contradict it. They only add in additional authentic expressions which Zayd did not include. Furthermore, TSN themselves have accepted statements not made by Zayd are authentic expressions. Please read their work here:
http://twelvershia.net/wp-content/uploads/2013/10/Authentic-Expressions-of-Thaqalayn.pdfScholars accepted it out of lenience because they are lenient in regards to ahadeeth of virtues. But when it comes to deriving rulings from these type of reports or basing a belief on them , then such reports are outrightly rejected .
SubhanAllah, not only have we broken down the chains and proven according to orthodox standards they would be classed as Hasan , TSN has agreed upon the first chain. Now if you are talking about 'Lenience' many scholars have graded versions and chains of this hadith as weak when they came through weak chains, and they explicitly stated 'The Chain is weak'.
For example: Jabir ibn Abdullah said, “I saw the Prophet (saw) during his pilgrimage as was on his camel speaking, so I heard him say, “I left you that you must abide by that you will never go astray, the book of Allah (swt) and my Ahlulbayt (a.s).”
Footnote: Sahih li ghayri(authentic due to external evidence),
the chain of this narration however is weak, because of Zayd Ibn Al-Hasan he is Qurashi and Al-Anmati.[Source: Jamia Tirmidhi Sunan Al -Tirmidhi. Vol. 6, Pg. # 335].
If there were weak narrators, al-Albani, Arnaut, and others would not state 'the chain is Hasan', but accept that the Chain is weak, but there may be external corroborating evidence. In fact, al-Albani explicitly grades weak chains of Thaqalayn as weak, but authentic due to external evidence.
What youpunctured/you are arguing is that in light of an authentic report, all of the weaker reports are graded as reliable because they corroborate with the authentic one in what they agree with. However they are in themselves not reliable. I am telling you that many major Hadith scholars have explicitly said 'This chain is Hasan', rather than saying 'Saheeh due to external evidence, although this chain is weak'.
Shaykh Shoaib Al-Arnaut declared the chain of this narration as weak, because of narrator Zayd Ibn Al-Hasan Al-Anmati. We find here that even though he weakened the chain of this report, yet he authenticated the tradition based on external evidence; those are authentic versions of hadeeth Thaqalayn, which are regarding the virtues of Ahlulbayt, that mention about taking care of Ahlulbayt and being responsible towards them.
However in the traditions i have quoted Al-Arnaut does not authenticate it based on external evidence, nor does he declare the chain weak but explicitly states the chain is Hasan. The only weakness in it is Kathir b.Zayd who is Saduq but makes mistakes, however, this is why it was demoted from Saheeh to Hasan. Had it been weak, he would have declared it weak, but said authentic due to external evidence.