Yes I think generally your post is correct and you obviously have far more experience than me regarding IQ tests as I know very little.
I do know that I would definitely fall into number 2 category because I like to think I am smarter than I am but deep down I know I'm average.
Maybe IQ tests have come a long way over the years but some years ago I did take an IQ test along with a business colleague. I scored far higher than him which in itself was ridiculous. My colleague was far, far more intelligent than me, he was one of these naturally gifted human beings who could just retain knowledge easily. He was and is a very, very intelligent person in many subjects and his general knowledge and calculating skills are probably the best I and others have ever witnessed.
Yet my IQ was higher than his ? Needless to say that I have not took a test since and probably never will due this silly result. It was almost comical that on paper I was supposedly more intelligent than my colleague when it was quite obvious that I wasn't in his league.
So as far as I am concerned these tests maybe (and just maybe) will give you an idea of someone's IQ but I wouldn't bet on it. My logic tells me that there is the distinct possibility that one could be 'lucky' with the questions.
My common sense also tells me that maybe my experience was an isolated incident and IQ tests are generally a good pointer as to how intelligent someone really is.
My honesty also tells me that maybe they are for people who either have a big ego and want to tell everyone how clever they are or they are for people who need the recognition and use it to achieve their goal.
Fortunately I don't fall into either category and really couldn't give a monkey's
I am sure some one somewhere earns big bucks for organising these tests and good luck to them.
Cofton