I have never looked at one of these bookings before so if someone with a knowledge of rtw reward fares is able to advise if this looks possible to book or can suggest improvements, it would be much appreciated. Also how do you book the seperate flights when they become available at differing times?
The Australian Frequent Flyer forum is also helpful if you have very specific questions + want to know more about the individual experiences of booking:
You can use the star alliance round the world booking tool to verify that your itinerary fits the requirements of the Singapore Airlines RTW reward as well as they are largely very similar. For finding award availability, you generally need to do this per segment. I.e. you need to find Sydney to Halifax then find Halifax to Dublin and so on and so forth. You can’t look for availability in 2025 yet, but I suggest you to look at a similar time period in 2024, and see what sorts of options are available to get to your destinations, then plugging those into the Star Alliance RTW booking tool to check eligibility, making sure there’s no backtracking or illegal routings etc.
You have to have a completed and legal RTW itinerary at the time of booking. Unlike the Qantas RTW trip, you can’t start an open multi-city booking and just turn into a RTW booking later on. Once you have a completed round the world booking, you should be able to modify individual segments within the booking for a change fee (note Singapore Airlines charges quite a lot for changes).
In terms of your destinations, I think you might struggle with some destinations.
Transpacific business class is always tough. When searching for awards to Halifax, you might need to settle on flying to Vancouver, LA, SFO, or other US gateways and then purchasing a seperate flight to Halifax. It’s rare you’ll have both a transpacific business class seat and also coincidentally a connecting flight available to a relatively minor Canadian city.
Air Canada’s trans-atlantic availability is similarly a desert. You might need to fly in to Frankfurt, or Geneva or any a number of star alliance hubs instead of Dublin. You could be connecting through them to get to Dublin, but if you are looking to go to that part of the world anyway, you could consider modifying your trip slightly to begin there and again purchasing your own flights to Dublin or redeeming some additional miles on short haul flights within Europe.
Similar advice when coming back. You could look at more than just Paris and accordingly plan your European portion. Let the flight availability dictate where you will land and depart out of Europe - this will give you the best chance of finding a suitable itinerary. Europe to Australia is always a bit challenging, but Singapore Airlines has been decent with availability!
TLDR: Keep your city pair options open. Usually, the bigger the city, the more options there are!
Note that the star alliance RTW tool is for a PAID round the world booking, not for the Singapore Airlines KrisFlyer RTW booking. BUT, because the paid booking and the points booking share similar rules, you can use the website to verify that any proposed itinerary is legally allowed to be booked.