You are totally right that the GMAT is full of traps. That's why it is so important to think like the test maker. There are a lot of hints for potential traps and once you know what to look for you will avoid mistakes and score higher.
We give to clients a list of words that indicate either a trap or should at least make the student suspicious. We teach these kind of things in our courses.OPTIMUS PREP
Artem Morgunov I Founder of Optimus Prep I firstname.lastname@example.org