Would "Eu ajut tatal meu" be correct / normal usage / a reasonable alternative, or is the redundancy which looks very odd from an English POV required?
"il" is used as mandatory in the sentence as one somehwere else said, pe tatal meu is to extra say, "I help him (who is my father)?" that's how it sounds in my brain : )
(eu) ajut tatal meu means i help my father and (eu) il ajut pe tatal meu means i help him, my father. people whose mother language cannot really understand it. My language is greek and it is something that we also use. same sentences in greek: (εγώ) βοηθάω τον πατέρα μου and (εγώ) τον βοηθάω τον πατέρα μου. second one is just to give more emphasis that he helps his father