Hello "Day",
today I received the third and last one free submission I need and now I'm able to calculate the norm (I hope to do this in about a month - at the moment I'm very busy typing a pure matheatics paper-), so the bad notice is the test is no longer free for all the testee. BTW it remains free for both the ERGOs and the sPIqr members. The positive thing is that there will be a stronger norm and the risk of cheating will decrease (even if normed tests are affected, generally, by an higher cheating risk).
Regarding to part three, don't worry... it's the most difficult of the whole test, I know. In that section, no one has reached 4/6 until now and the sixth item is (IMHO) "really hard"

The best,
Marco