6. I have never and will never pay that 30BTC, as I've just said, its ridiculous. I have heard MPOE and Pankkake's argument for it and I don't think it holds in any context.
There are two reasons for the 30btc fee which are much simpler than you'd imagine.
First reason is simply profit (almost all of which going to mircea himself). 30btc profit per new user is more than most companies can say.
Second is referral scheme. You and your referral get 10btc back each every time you refer someone.
Without the fee there would be nobody to perpetuate the scam.