Not sure if your point regarding Tipperary is in jest or serious - given the fact that most of the line is upgraded to continuous welded rail and that even now it offers a journey time broadly similar to the road journey (and notably faster for most sections than the Bus Éireann route 55 Expressway) it would be ridiculous if services on the Waterford-Clonmel-Limerick Jct. line cannot be accelerated.
Personally feel that the timetable on the line needs to be reconfigured to facilitate commuter traffic into Waterford as well as its current main purpose in feeding into the Dublin-Cork service at Limerick Junction. Plus run the trains to/from Limerick city. Some would say add a Clonmel to Dublin through train.
If the powers that be are really thinking of ceasing the entire service on lines then it needs to be done fairly and transparently meaning that Ballybrophy-Nenagh-Limerick and Ennis-Athenry should be looked at before Limerick Jct. - Waterford.