As always, a good post and you provide something to make people think.
"I have completely changed my attitude towards parasites- they are smart, very very smart and very dangerous."
Who would have ever considered that these buggers are SMART, or have the instinctive sense to survive so well. I hate to admit it, but worms have outsmarted me on more than one occasion.
"But the question is, does everyone need to kill parasites? But more important, can we kill them with the compounds available out there?"
I think, your last question is an excellent one. The "compounds" do need to be examined more closely -- people need to get better, not worse.