Re: Cork
OP, One other option is to buy a 'weekender' ticket from the train station. It costs €6.50 I think (you'll need a photo), but will reduce your fare from €59 down to €38.50. Irish rail never seem to advertise this card but as you gain back the price of it on your very first trip then I think its worth it.
Traffic at any time through Fermoy seem to be just brutal, I dont think the Fermoy bypass is open? The Mitchelstown bypass should save you a few mins alright though.
If you haven't already, I would check out if there are any concessions for OAP's travelling by train - surely there is something?
Best of luck, enjoy!