Misconception 1: «أَبٌ» is always nominative with wāw.
Correct: Without iḍāfa, «أَبٌ» takes ordinary vowel case signs.
Misconception 2: The yāʾ in «أَبِي» must always indicate genitive.
Correct: It is the first-person possessive pronoun and occurs with different syntactic cases.
Misconception 3: Every «ذَا» must be a demonstrative.
Correct: In «ذَا مَالٍ», it is the accusative of ذُو.
Misconception 4: A genitive second term forces the first term to be genitive.
Correct: The first term's case depends on its own syntactic role.