Is there such a right explicitly or implicitly  guaranteed in the Irish Constitution? Even if there is a lifetime ban on positions of fiduciary responsibility does not prevent one from making a living - just from doing so with other people's money.

"It is not necessary to have hope in order to persevere."

I do know that Michael Milken is effectively prohibited from ever again working in the financial industry personally. But he still got to keep $500 million in assets and cash. I think a million would have been quite sufficiently generous and certainly no more than $10 million. He did far more damage than that via the junk bond scandal, and $440 million might have gone a ways towards compensating some of the victims, preferably starting with the most vulnerable.

"It is not necessary to have hope in order to persevere."

Does this mean that reckless drivers get to keep their licence in Ireland if they need to drive for their living? Or does the Irish Constitution have a special clause protecting bankers?

No such right in the US.  We take away the ability to make a living above the poverty line with every felony conviction.