Fathers punishment and how to ease the punishmnent

As salaam ualaikum. Respected Mufti,
My father passed away 6 months ago. Despite his illness he had a very “easy ” death. I have 2 questions:

1) My father was not able to read the quraan, however he could follow along if a Surah was being recited aloud. He would read his Salaah as my mum had taught him. He could make zikr. How will my father be punished and how can I help to ease my father’s punishment.

2) My uncle died from the same illness he suffered for 5 years ( my dad only 5 months). My Aunt always compares. She is convinced someone did something that’s why he suffered for so long. Please advise. Shukraan