conditional constructions - Correct usage of "If I were"

Which of the following sentences are correct?

1. If I was him, I'd buy a car later when I have money.


2. If I was him, I'd buy a car later when I had money.


3. If I was in her place, I'd ask the kids if they want another animal.


4. If I was in her place, I'd ask the kids if they wanted another animal.

I think the second and the fourth ones are correct. But I'm not sure if the others are wrong.

Answer

In formal use all of these require were for the condition (IF) clause, because they are all "counterfactual", conditions "contrary to fact": you are not him, you are not in her place.

You have correctly employed "I'd" (= I would) as counterfactuals in the consequence (THEN) clauses.

The tense in a subordinate clause is not necessarily determined by the tense of a main clause, so the "want" and "have" clauses may take either the present or the past form: depending on circumstances, the "facts" (having money later and wanting another animal) may be regarded as either doubtful or certain.

But in colloquial use all are acceptable.