Both ahadith about Abu Bakr and Umar, Hassan and Husain are not authentic.
The one about Abu Bakr and Umar =
قال رسول الله: عمر وابوبکر سیداکهول اهل الجنة
It was collected in Sunan ibn Majah and similar ones in Jami at-Tirmidhi.
Isnad from Sunan ibn Majah =
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا سُفْيَانُ، عَنِ الْحَسَنِ
بْنِ عُمَارَةَ، عَنْ فِرَاسٍ، عَنِ الشَّعْبِيِّ، عَنِ الْحَارِثِ، عَنْ
عَلِيٍّ، قَالَ قَالَ رَسُولُ اللَّهِ
هِشَامُ بْنُ عَمَّار is not reliable and he often makes mistakes as mentioned by Imam n-Nasai.
ْ الْحَسَنِ بْنِ عُمَارَةَ he was abandoned and his narrations aren't accepted.
الحارث His full name was الحارث بن عبد الله الأعور and he was known to be a compulsive liar.
So this narration from Sunan ibn Majah is completely rejected.
There are other ones in Jami at-Tirmidhi which were declared as strange by Imam at-Tirmidhi.
As for the one mentioning Hassan and Husain being masters of youth in Paradise. They're also inauthentic and cannot be proven to be true.
The isnad from Jami at-Tirmidhi =
حَدَّثَنَا مَحْمُودُ بْنُ غَيْلاَنَ، حَدَّثَنَا أَبُو دَاوُدَ
الْحَفَرِيُّ، عَنْ سُفْيَانَ، عَنْ يَزِيدَ بْنِ أَبِي زِيَادٍ، عَنِ
ابْنِ أَبِي نُعْمٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ،
First problem is سفيان whose full name is سفيان الثوري and he was mudallis. He's a reliable only when he narrates ahadith by saying he heard or he was told. But not when he says "from - An" as he did here. Therefore, it's not accepted.
Second problem is يزيد بن أبي زياد and he was declared as munkar al hadith by Imam al-Bukhari.
Therefore, because of these two people, this hadith is not authentic.
There are other isnad and Imam at-Tirmidhi said they were strange.
So both of the reports you've mentioned are rejected.