The question/claim: "Are the 7th/40th/52nd-day rites, holding a mawlid recital, distributing halva/dough-balls a command/obligation of the religion? Or a cultural ceremony?"
What does the Qur'an say? — each is responsible for their own deeds
"No bearer of burdens shall bear the burden of another." (53:38)
"And that man shall have only that for which he strives." (53:39)
These verses stress that responsibility is personal; "a specific day/ceremony after death" is not commanded in the Qur'an.
Separate two matters
(1) Prayer/charity for the dead — conveying reward (īṣāl al-thawāb): multi-vocal
- Those who permit it (the majority — Ḥanafī, Shāfiʿī, most Ḥanbalī): hold that the reward of prayer, charity, ḥajj/fasting done for the deceased reaches them. Evidence: the Prophet permitting those who asked about charity/fasting on behalf of a parent (Bukhārī, Muslim). On this view 53:39 describes a person's own earning, and does not exclude another's prayer.
- Those who read it more strictly (some Salafī/academic): relying on 53:39, are cautious about another's deed being credited to the deceased; while accepting the benefit of prayer/charity, they regard "donating the reward of recited Qur'an" as contested.
(2) The fixed day and ceremony: cultural
- The 7th/40th/52nd-day numbers, the mawlid-recital ceremony, the halva/dough-balls custom — these do not appear in the Qur'an or Sunnah as a specific day or form. They are regional custom (some from pre-Islamic Anatolian/Persian practice).
An honest limit
- With a basis: praying to God for the dead and giving charity on their behalf — a widely accepted (though somewhat contested) practice.
- Cultural: "a mawlid, halva and set ceremony exactly on the 40th day" — the number and form are not a command of the religion but a cultural custom; the belief that "if not done the dead is restless" has no religious basis.
Conclusion: prayer and charity for the dead is a good deed with a basis (the majority permit it). But the 40th/52nd day, the mawlid ceremony and halva are not a religious obligation — they are a cultural tradition.
Source: Qur'anic verses (M. Okuyan meal) + Sunnah (charity/prayer for the dead). Views on conveying reward are given multi-vocally, separated from the fixed days/ceremony. Not a fiqh fatwa.