" Who is the idol of duel academy ? " (Alexis / DMGirl / Dorothy / Pharaoh)
I chose DMGirl (not Alexis) and I still got 100% test result. If I were to nitpick, Alexis is not the answer. Somewhere AFTER test 2, you could talk to Bastion at the Cliff and he will tell you that Vellian is currently trying to make Alexis the idol of the academy. That means Alexis is not the current Academy's idol; although I couldn't remember if any NPC ever mentions who the idol is or not. It matters not anyway, as the tests themselves do not affect the game.
Test 2 was a bit of a stumper for me (grrr...) because of this ambiguous question :
" Up to how many Equip cards can be on 1 monster? " (5 / 10 / 20 / No Limit)
For the longest time I thought the answer was 10 (as you could equip enemy's monster with your equip card in your S/T zone). After beating Sigthor again and again and again, I gave up and made a trip to GameFAQs to find the correct answers. Geeez, Konami should have reworded that question and made it less ambiguous...