The Newcastle-Sydney timetable is 2 trains per hour on weekdays. Departure times from Newcastle are  not evenly spaced. On arrival in Sydney ask for a Central Coast timetable  and a Hunter Lines timetable at Central Info Centre on the main concourse. Weekends every alternate service terminates short at Wyong.

To get to Thirlmere by pubic transport:

This requires an early start. Take a Macarthur via Airport train to Campbelltown where you change to the Moss Vale train. This train connects with a bus at Picton. The departure time from Campbelltown is 8.50am. The latest connection departs Central at 7.50am. There are several departures from Central in the 40 minutes to 7.50am. The bus does not accept Opal cards but will issue a railway ticket to Thirlmere, A separate fare may need to be paid. Tell the driver you are visiting the Museum. The bus is only about 10 minutes to Thirlmere. The Museum opens at 10.00 so there is time to get a coffee from the nearby shops. Ask the Museum receptionist if there will be a visiting group that day. If so there will be a tour guide and you should be able to join one of the tours. Buses return to Picton at 1.20pm and 5.10pm. There are other buses to Tahmoor between these services. There is not a common bus stop in Thirlmere so you should ask for guidance.
This all sounds complicated but is not too bad. There are no bus services at weekends.

At Thirlmere there is a classic American style Buffet Diner car which is open for internal inspection.

Isn’t Tarana a stop on request stop ? Like Rydal ? I’ve been picked up by the XPT at Rydal but I did book. Both villages have the advantage of a pub with a beer garden a stone’s throw from the station.

It’s important to keep hydrated between lulls in passing trains.

Northwest, you can hop off the train at Lapstone and a walking trail will take you around to Glenbrook Gorge. Nice and easy. I go there a bit. It’s worth going to the edge and having a look over. But hold onto something.

Gladys should restore the lines that have been ripped out of Rydal and Tarana. With more pax services and freight moments promised, the second platform (and adjacent track that is currently missing) could be useful. Pax can leave the train for some fresh air in the event of an extended delay. I guess Rydal won't directly see the crossing loop as it is going to be 3km away... Go figure, while Georges Plains station will have one directly outside. Does this mean XPT/XPL services could stop there if they are waiting for freight to clear the tracks?

Gladys should restore the lines that have been ripped out of Rydal and Tarana. With more pax services and freight moments promised, the second platform (and adjacent track that is currently missing) could be useful. Pax can leave the train for some fresh air in the event of an extended delay. I guess Rydal won't directly see the crossing loop as it is going to be 3km away... Go figure, while Georges Plains station will have one directly outside. Does this mean XPT/XPL services could stop there if they are waiting for freight to clear the tracks?

If ever the volume increases it could all be easily put back. Right now there are so few trains that the passing loops will suffice.

Gladys should restore the lines that have been ripped out of Rydal and Tarana. With more pax services and freight moments promised, the second platform (and adjacent track that is currently missing) could be useful. Pax can leave the train for some fresh air in the event of an extended delay. I guess Rydal won't directly see the crossing loop as it is going to be 3km away... Go figure, while Georges Plains station will have one directly outside. Does this mean XPT/XPL services could stop there if they are waiting for freight to clear the tracks?

I'm sure that's all very helpful for our overseas friend in planning his trip

I couldn't help myself, ... no point going main west when it has been gutted by successive governments....