Train travel within cities..

I am trying to organize my April trip to Europe (first time). We are planning on visiting Dublin, London, Brussels, Amsterdam, Munich, Prague and possibly Berlin. I am confused about the trains though. I believe that point to point tickets will be cheaper than a Railpass, but with the Railpass we would be able to take short trips within the cities, is that correct?If we go point to point, how would we be able to travel the train between cities while inside the different countries? Thanks.