The bar for getting on the ballot is ridiculously high in Ireland.

The endorsemet of 20 sitting members of the Dáil (parliament)

Or the endorsement of 4 local councils

It's incredibley unlikely that he will get on the ballot.

The role of the Irish President is basically to shake hands and as a sort of ambassador. It's almost entirely ceremonial. They sign things into law but cannot actually vetoe legislation put forward by the governent.

The President's powers include:

Appointment of the Taoiseach, members of the Government, judges and other officials;

Summoning and dissolving the Dáil (parliament), and convening the Oireachtas (wider government)

Signing legislation into law and/or referring Bills to the Supreme Court; (again, no vetoe powers)

Representing the people of Ireland;

Acting as Supreme Commander of the Defence Forces.