Tense simplification in the present or future irrealis conditionals

PEU¹ 580 tense simplification in subordinate clauses

Past (form) instead of would...

Would, like will, is avoided in subordinate clauses; instead, we generally use past verbs. This happens in if-clauses, and also after most other conjunctions.

If I had lots of money, I would give some to anybody who asked for it.
(NOT If I would have... who would ask for it.)

Would you follow me wherever I went?
(NOT ... wherever I would go?)

In a perfect world, you would be able to say exactly what you thought.
(NOT ... what you would think.)

I would always try to help anybody who was in trouble, whether I knew them or not.

I'm wondering why all these examples are in the past tense, not the present tense, as they sound more like direct speech of the present or future irrealis conditionals.

I would have thought they should be:

If I had lots of money, I would give some to anybody who asks for it.

Would you follow me wherever I go?

In a perfect world, you would be able to say exactly what you think.

I would always try to help anybody who is in trouble, whether I know them or not.

^{1. PEU = Michael Swan's, Practical English Usage.}

Answer

The past tense is allowed because at point in time at which you are deciding to do something (as described in the independent clause) the condition of doing something will have already been satisfied.

Imagine saying the first sentence as you in the future, in which case you would be speaking in the present tense: If I have lots of money, I would give some to anybody who asked for it.

Somebody has asked for it (in the past) and I (presently) have lots of money, so I will give some to them.