The hadith which says righteous humans are superior to the angels was attributed to Prophet Muhammad via weak isnads.

We do not know of any sound hadith from Prophet Muhammad that says: “There may be someone who recites the Quran but the Quran curses him.”

Two hadiths have been reported form Prophet Muhammad (peace and blessings be upon him) about the virtues and benefits of Surah Taha. However, there are many weak hadiths about the virtues of the Surah. For more, please see the detailed answer.

The words that were attributed to ‘Ali (may Allah be pleased with him) – Did you come to know your Lord through Muhammad…? – are words that are to be found in the books of the Shi‘ah as part of a long story. The evidence that this is a lie is obvious in this report, as they use it to impugn Abu Bakr and ‘Umar (may Allah be pleased with them) and cast aspersions on their knowledge, and they narrate it with an isnaad that is not free of narrators who were accused of lying and narrators who are unknown.

there is no sound hadith or report which states how old the Mahdi will be when he appears.

Thinking to oneself whilst praying about things that have nothing to do with the prayer detracts from its reward, but it does not invalidate the prayer altogether.