My friend says Busses are better, nicer routes and single pricing rather than trying to figure out how to get a discounted train ticket.
I respectfully disagree with your friend. With the exception of Coimbra to Tomar, the trips are easy and cheap on the train. And, getting discounted tickets is simply a matter of booking up to a month ahead of the trip. The cp.pt website has the option for English and is quite easy to use. Try to get the AP trains.
The trip from Coimbra to Tomar requires a couple of changes but the others are one train and the most expensive is Lisbon to Aveiro which is 12€. The trains in Portugal are quite good. I would definitely use trains for all except Coimbra to Tomar.