Learn English – would have been sitting/would have sat

Well, both sentences are grammatical, but they mean different things. It depends on what you're trying to say.

The first means, that if you had money, you'd fly there now or some point in the future.

The second can mean one of two things, depending on whether "had" is intended to be 'hypothetical' or a genuine 'past reference': so it could mean either (a) if you had money (now), you would at some point in the past have flown there; (b) if, at some point in the past being referred to, you had had money, then at that moment or some moment thereafter, you would have flown to Spain.

As I say, it's not really a question of one sentence being grammatical and the other not, rather that they have different interpretations.

• If he hadn't done well on the training courses, he wouldn't be a Project Leader now.

The key word is now. He is now Project Leader but would not now be Project Leader if he hadn't done well, etc.

Imagine that he was Project Leader, but is Project Leader no longer. He is not Project Leader now. Then it is correct to say:

• If he hadn't done well on the training courses, he wouldn't have been Project Leader.

The same principle applies to your other examples:

• If you had gone over that question in your note-book, would you be able to answer question No. 2?

This is a question about what you would be able to do now.

• If you had gone over that question in your note-book, would you have been able to answer question No. 2?

This is a question about what you would have been able to do then.