Navigating the trains was really easy as they have signs for everything in English. We had no issues at all. If you are planning on taking a train in the morning, you should not have any difficulty to follow the same steps back in the evening.
We stayed at Toy Story Hotel and our experiences with taxis were only about going from the airport there and back. At the airport there is an official taxi stand and that worked well. The driver spoke no English, but we showed him the print out of the Toy Story Hotel address in Mandarin and he recognized the Mickey head and immediately knew where to go. On the way back the hotel got the taxi for us and that taxi was incredibly old and had no functioning seat belts. We got to the airport ok though.
With my experience, I would feel more comfortable taking the train if at all possible instead of a taxi. I found it more nerve racking to not be able to communicate with my driver because of the language barrier than looking for the English language signs on the trains.