Learn English – “I’d rather she has’ vs “I’d rather she had”

If the question is, are you correct in assuming that your last example is correct, "I'd rather he had called me before he paid me a visit," then you are correct.

If you were to use the simple past in your example sentence, "I'd rather he called me before he paid me a visit," that would mean that you, in general, would prefer he called you before visiting, and that it's occurred at least once in the past. The use of past perfect makes it clear that you're talking about one action that preceded another single past action.

Reading the sentence aloud (always helps) led me to conclusion that you wouldn't change the phrase for the past tense.

'As if she were is an example of the imperfect subjunctive; she isn't all there is to his life, but the context considers the hypothetical possibility of it, so we stick that tense in there.

Regardless of which tense you're writing in, the imperfect subjunctive is still the imperfect subjunctive. The perfect tense doesn't work as a replacement in this case.