"свести с ума" и "сводить с ума" - огромная разница

похоже, речь не идет о реальном сумасшествии, а имеет фигуральное значение, поэтому оба варианта равноценны

на мой взгляд, ваш перевод это как раз и не передает
это свело его с ума - реально
это сводит его с ума - фигурально

поскольку условие нереально, то это дело вкуса

Здесь может быть и: чувство вины сводило его с ума (постоянно в прошлом).¿

There are two possible interpretations: (1) In the present time, if he found himself in a hypothetical situation, it would potentially drive him crazy - in the sense that it would torment him tremendously -or- he would literally lose his mind. (2) Speaking about something that happened in the past which the writer/narrator already knows the outcome of and which eventually DROVE him crazy (in the same two senses above). Writers and narrators often use this WOULD speaking about the future in the past, just like we use WILL to speaking about the future in the present: "Lena was furious when she missed her flight and was stuck at the airport for five hours until the next one. But fate had something else in mind. Sitting at the bar, waiting for her flight, she would strike up a conversation with the young man sitting next to her which would change her life forever. This young man would become her husband a year later."

So if we go by (1) we would be speaking hypothetically: "Although it seems like a foolproof plan to get the money, my father would never go through with it - the guild would drive him crazy. (=we would never get over the feeling of guilt). And if we go by (2), then this already happened: "It was a foolproof plan. My otherwise honest father saw the theft as an opportunity to put his children through college, but the guilt would drive him crazy. A year later he took his life." (=the guilt DROVE him crazy and he eventually killed himself)

The only difference between Grumbler's and Valery's translations is that the former implies the ongoing action, while the latter implies the instant action.

Then I would go with Grumbler because this is about something taking him to the point of losing his mind.

Let the context be the judge

Улий, спасибо за объяснение!))