Will someone who died after a struggle with illness and was pious, righteous, and a devoted worshipper of Allah enter Paradise, and will he feel what happens to his family?

If a righteous Muslim dies, Paradise is hoped for him, but it is not definitively asserted for him, just as forgiveness is hoped for him through trials and illnesses. We do not know of anything that indicates the deceased's awareness of what happens to his family after him; rather, it appears that his connection to this world is severed.