Alan ,
44 years and old enough to have heard of all those products and used some of them .
Off the top of my head I believe only one of the products you mention (picloram) is currently registered in Australia . Why ? Because the others have either been proven to cause environmental damage , have user safety issues or because of the agent orange / dioxin scare . BTW , 2,45-T , 2,4-D etc. can be (and is) manufactured now without that contaminant .
You will note that I pointed out that currently registered products are well researched . There is no doubt that some early pesticides were unfriendly to both the user and the environment . They were not subjected to the rigorous testing that pesticides are now , nor were farmers well advised on how to use them safely .
Alan , I hear as much criticism of pesticides as I do of firearms . The reasons people are critical are largely the same in both cases .
FYI I live in Wheatbelt W.A. and outside the 44 years of experience that I have had as a farmer , in related industries and as a hunter I don't claim any qualifications in control of vertebrate pests .
Other pests are a different matter . 18 years with one of the world's largest ag. chem. companies providing advice on how to use their large product range (including personal and environmental safety issues) . Good enough ?