It's pretty much standard for the industry, not just Blizzard, though I agree that such pricing models suck. I don't understand why that problem hasn't been swept away already across the board, but such regional bullshit seems to remain prevalent. How do people not understand currency conversion rates? This baffles me.
Also, the only thing you get for predordering is the worthless cosmetic wings which I believe they only provided to keep a vocal minority from bitching about something or other. So you're really not missing anything at all.
As for the difficulties ... Pug, there were originally 4 difficulties. Normal, Nightmare, Hell, and Inferno, and getting from one to the other required a complete play through the campaign. Thus you had to play the campaign 3 times to get to Inferno with any character, where the real endgame actually began. This was changed to 5 difficulties, Normal, Hard, Expert, Master, and Torment (Torment having 6 variants ... I guess the naming convention was just an expedient), but now you can play all of them any time you want, except for Torment, which unlocks at level 60 (though you only have to unlock it with a single character). I have no idea how this changes public games as, again, I don't play them or have any desire to. It's a much better system overall as far as actual gameplay is concerned. I routinely bump my characters to Expert by level 17-ish, and Master usually by 25 (though this is much tougher now with the big experience bonus, as you level much faster—thus the enemies do too—than you can reliably upgrade all your gear, though crafting helps mitigate that a lot, which is nice if you've got a bunch of stuff stockpiled like I do), so the drop quality and rewards scale up nicely, and the game is more fun to play when it's tough. Hardcore is a blast now because there are a lot more genuinely terrifying situations to get into.
