Veltz,
It is not that I don’t think “intelligence” has a definition. I am uncertain as to whether there is such a thing as “general intelligence” but I think that when people say “X is an intelligent person” they do mean something (even if that thing is a “bundle of sticks”).
I don’t think IQ tests any aptitude other than the aptitude to take IQ tests. That aptitude is correlated with success in other areas but the correlation is far from perfect. There are people with high IQs who are a failures or average in those areas and there are people who excel in those areas without very high IQs.