Hi Zampa,
I did not say you should use an 8 foot pole-gun, which I agree would be too long for most jobs. The usual size is 1 metre (39.4") which you will probably hold at 60 degrees with the trigger at your side about 1 metre off the floor. That way the spray head is about 50 cms above your head.
Its true that US painters are more into spray painting, they usually learn from their dad. But so do Australians.
If you are using a solvent based paint, you will need about 5 litres of solvent first time, but you make several flushes of about 1.5 litres and keep the last 2 to reuse the next time as the first flush etc.
I would say that water based masonry paint takes a little longer to flush than emulsion, but you don't need lots of water to do it, nor does the machine have to be perfectly clean, in fact you should leave the water (or solvent) in it to stop any residual paint drying out, but if you leave water in the machine for more than a day or so, you should add inhibitor to the last flush water.
As for the dangers of airless sprayers, you are talking about an injection injury. Fortunately they are pretty rare, but serious if they happen. What you may not know is that you can get the same injury from a pressure washer. To be frank, you have to do something stupid to get an injection injury. There are quite a few DIYers that hire airless equipment without problems, just ask HSS, Speedy, Hewden etc.
Whether airless spray is the right way for a DIYer depends a lot on their budget and time, but it is certainly the fastest way to apply paint, usually gives a better finish and often saves paint. But its not magic and an efficient masking machine with professional tape is part of the secret.