Between the time taken to slow down, stop and speed up again I suspect it maybe closer to 5 minutes. Anyway, I really fail to see how the addition of a Moyross station/ stop would be of significant value to the viability and success of the WRC, both from a passenger and revenue viewpoint. Has the RPA or IE undertaken a feasibility study on passenger volumes? What proportion of passengers will be fare paying / free travel scheme recipients? Adding a spur to Shannon airport, for example, would be of far greater benefit to the WRC.
The additional time added to a journey arising from an additional stop along the route is 3.5 minutes if you were to go by IE's own timetables for other routes. Take the timetable for Dundalk and the difference in journey time between intercity trains serving the town and suburban commuter trains serving the same town divided by the number of additional stops between the two services. See for yourself.

IE have made no secret of the fact that they don't think the western rail corridor is financially viable on it's own (then again what train service is?)

The point is; anyone in favour of the western rail corridor (I would imagine most locals are) should also be in favour of as many stops along the route where there is a concentrated population density. Otherwise the new route will be more unprofitable than it needs to be and greater the chance that in such a situation when the exchequer returns are tight it will be one of the first routes on the IE network to go.

The Moyross stop makes even more sense when you account for the fact that car ownership is lower in areas where the social profile is predominantly working class. In itself it will contribute to reducing social exclusion in the area which is the whole point of the regeneration initiative. I would imagine posters on this thread, if they're the type to have some Victorian notion of trains only being associated with the seaside and holidays, are probably not the type to use trains all that often so I really don't see what all the objection is about.