Tax on self employed income plus ARF

Yes, obviously he's entitled to the Earned Income Credit but I can't for the life of me work out what relevance that has to your question.
A friend of mine recently turned 61 and has started drawing an ARF ( Zurich Life) worth approximately €4000 gross per month. ( mandatory)

He is continuing to work as a sole trader. His spouse , 62 , has stopped working . Four grown up kids who he'd like to help out from earned income at different life stages.

What tax credits and cut off points is he entitled to and how does he distribute them ?

I had two questions in my original post. That was the first one, Tom.