Regarding the repeat questions, I looked up your tests based on your username and saw three tests - one 670 like you said and one that starts with a different hundreds digit (so not a 690) and a third that's in progress with no score. And there weren't any repeat RC passages in there, but then again your 680 wasn't in there either. So...I think what you're experiencing is something that a few others have before - since there's no difference between the "Free Test" question pool and the "Paid Test" question pool (the paid tests just have more tests), if you take the free test under one username and then start your paid tests under another username, you WILL see repeats because the system doesn't know to exclude the questions you've already seen.
The system is designed to prevent any one USER from seeing the same question twice, so if you take all your tests on the same account you shouldn't see that problem.