What is the ruling of Islamic scholars concerning the following:
1. Is it right and permissible for sunnis to narrate the events of karbalā in the manner of the rafiDīs [and purposefully] not mentioning the four rightful and guided khalifas and other Saĥābis who perished in karbalā? nor to mention abū bakr, úmar and úthmān the sons of áliy karramAllāh wajhah [because they are named after the three khalifahs]?
The best of all remembrance  is the remembrance of Allâh; and best of such remembrance is Salāt. Yet, even Salāt is not permissible and forbidden if performed in the manner of the rāfiDīs. The gatherings of muHarram and the narration of the events of karbalā – as is prevalent among the general populace – which rekindles grief and causes moaning and wailing, and such reports which are blantant lies and forgeries – which are in itself Harām – is [certainly] Harām.
It is in ‘as-Sawāyiq al-Muĥriqah’  and ‘mā thabata bi’s sunnah’:
“beware! beware! do not indulge in the innovations of the rāfiDīs of mourning and grieving and wailing – these are not the virtues  of a believer.”
Yes, the narration of authentic reports and in a permissible manner extolling the virtues and praising the high rank of sayyidunā imām Ĥusayn, the perfume of RasūlAllāh śallAllāhu álayhi wa sallam is certainly light of the sight, and sightly light itself .
But to stop only at that, and not to mention the four rightly guided khalifahs, particularly in places like lucknow  which is the indian kūfā , is certainly worthy of censure and is necessary to abstain.
The first type of gathering  Hujjatu’l islām imām muHammad al-ghazāli quddisa sirruh says :
“it is Harām for the preacher to narrate [forged] events of the martyrdom of Husayn”
Imām ibn Hajar al-makki says in as-Sawāyiq al-Muĥriqah:
“The ruling that it is Harām to narrate events of Husayn’s martyrdom doesn’t apply here in this book when I have mentioned the same because it is the truth and it is necessary to believe it; since it extols the importance of the Saĥabah rađiyallāhu ánhum and exonerates them from slander. This is opposed to the ignorant preacher, who narrates falsehoods and forgeries and doesn’t clarify the truthful ones which are necessary to believe. this causes the public to undermine or suspect certain Saĥaba”
The second type  is that which according to kitāb al-áwn and sharĥ an-nuqāyah at the end of the discussion of disliked actions .
“If one wishes to narrate the events of Husayn’s martyrdom, it is necessary that he recount the martyrdom of other companions  so as to oppose the manner of the rafiDis. This is because they are content with the martyrdom of Husayn, whereas the ahlu’s sunnah revere both the Sahaba and the ahl al-bayt”.
The mother of believers sayyidah áāyishah rađiyallāhu ánhā said:
“you should mention úmar, when you talk of the righteous” 
As for not mentioning abū bakr, úmar or úthmān just because they are named after the three khalifahs is open heresy, the trait of the rafiDi, and following the illusions of the rafiDis [may Allâh disgrace them] of this age. These names are pure, and “may Allâh destroy them, where do they wander away?”
There is a sect called bey-pīrey and they do not call monday by its other name ; nor do they make three doors for their masjids since it is the number of the first three khalifahs. it is such silly superstitions that prompted imām shafiýī to remark: “the shiáh are old wives of this nation” 
Allâh táālā knows best.
Answered by Imam Ahmad Rida Khan (رحمة الله عليه)
Translated into English by Shaykh Abu Hasan (may Allah preserve him)
[note: this is a longer fatwa with two more questions. only the first question has been translated.]
2. chapter 11. ibn Hajar al-Haytami’s masterpiece; a comprehensive and the most important accessible work in refutation of the shiáh.
4. nūr-e-áyn aur áyn-e-nūr
5. a prominent city in northern india; the urdu spoken here is considered as the sweetest and the most fluent. in fact, an idiom among urdu speakers is: ‘he speaks lucknow urdu’ indicating fluency.
6. which is true to this day: there is no city in india which laments the population of rāfiDīs like this is one.
7. imitating shiáh
8. as indicated in as-Sawāyiq al-Muĥriqah; يحرم على الواعظ وغيره رواية مقتل الحسين
10. kitāb al-karāhiyah.
11. like úmar or úthmān or Hamzah – they are among the leaders of the martyrs.
12. musnad imām aHmed. vol.2/p.148.
13. al-qur’ān 9:30
14. monday has two names in urdu: pīr and do-shanbah (from farsi); pir has also two meanings: ‘monday’ and ‘master’. bey-pirey means literally ‘no monday’ or ‘no leader’.
15. ash-shīáh nisā’a hādhihi’l ummah. there is no reference given. [because old maids are known for having superstitions and illiteracy rampant among women in olden days – hence the english phrase: old wives’ tale.]