QF 737s are always taxied by the Captain. For some reason, TAA never installed the nose gear steering controls on the FO's side in their aircraft, and that has been carried on with all of the later 737s as well. All of the bigger types are taxied by the pilot who is doing the sector. There are lots of things that affect the speed used. Sometimes you need to waste a bit of time, as the gate isn't ready, or heading out to the runway to give the cabin crew time to get the cabin ready. In close to terminals, it's a good idea to slow down. On long straights you can accelerate up to about 30 knots. Perception varies too. The little jets always seem to taxi faster than the big ones, but that's often an illusion, caused by the fact that you're a lot closer to the ground. The Captain chooses who is doing a given sector, more or less at his whim, though most simply do alternate sectors.
There is an extremely wide range of what pilots consider an acceptable landing. Smooth isn't even in the first few criteria, even though it's what passengers and cabin crew judge by.
Autolands are generally very smooth. If fact we actually allow extra distance on the landing calculations as they tend you use up more runway than manual landings. The 'gent' was almost certainly wrong. Autolands can be done on some runways in Sydney, but I don't know about Coolangatta. In years past it didn't even have an ILS, but I haven't been there in a long time.
Different aircraft do land quite differently. The 747 generally settled down very smoothly. The 380 is a little firmer, but still quite smooth. The 330 seems very 'floaty', and the 767 is, like all sports cars, very firm.
My criticism of Australian runway aids in the past wasn't so much that you couldn't do an autoland, but that doing so got you to no lower a minima than a normal manual landing. CAT II/III and GLS autolands are slowly appearing here now (well Melbourne has the CAT II/III, and Sydney the GLS, though it's minima are still extremely high).
