Many thanks. Not sure of the local airlines but hear Astana is ok.I’m Melbourne based. I used Singapore Airlines to get to Turkey, which I did a tour of as well, and Turkish Airlines from there..
Both are very good airlines.
The fitness level is out of 5 using the rating from G Adventures. In reality just reasonable mobility is fine but you might have to not do some of the activities.
It’s a great region to visit that I highly recommend.