From Hollywood to Newgrange is approximately two hours of driving. If you want to be one of the lucky ones to actually get in to the tombs, you should really be there just at opening, which would mean a very early start from Hollywood. To try and fit all of what you have listed in one day, given the early rising and all, would for me, be too much

From Aghabullogue, you can do the Bear can one full day...again an earlier start makes for more stopping points... In May, you are getting in to longer days once again...which gives you more "before dark" time