I can bet that much more than half of users didn't ever read the fundamental rules of BTT - you can see it in Meta board - there are hundreds of threads asking how to get merit, how to rank up, why i was banned, what is plagiarism, wy i can't put a image etc. That's why I think the idea of OP is not bad in general...
That wont do much. So yea it might require you decent knowledge to pass the "exam", but then what? A few days later then the answers would be leaked, rendering the "exam" useless. If they don't read the rules, then too bad for them. They will be banned in no time.
I'm not sure... I was thinking about something very similar earlier, but not as condition of registration rather as condition of promotion to Newbie rank (or get first Merit but this case Jr. Member requirement should be risen to 2 Merits).
I though about it as kind of walkthrough activity, were the question shows in random order. I'm not sure if it could be done in this forum software - maybe randomly generated questionnaire or maybe it would require external software....
But what's important - we don't have to worry that answers would leak - the purpose is not make users to learn them by hart or to write them in their own words - the purpose is only to make users to read the rules (random order of questions would enforce it). I'm sure that enforcing people to read the rules would rise their awareness and also would help them to avoid of being banned.
Another advantage (if this walkthrough activity would need at least 15-20 minutes to be passed) of this solution would be making life of bootfarmers (multi signature spammers) little bit harder as well...