Double post, but.......
On the philosophy of card game design, I'm not sure if they've got it perfect with Hearthstone, but it's better than most. Let's face it, it's a CCG, which means that having better cards than your opponent in your deck will make winning easier. Bloodfen Raptor vs any other 3/2 2 drop with a text box is the easiest example. It's a simple upgrade to anything with a text box (although in a face-roll hunter deck it is great. It has a text box. Beast). Although, it's not a bad card in a weeny deck, there's just better ones, plain and simple.
PTW? Not really. Pay to accelerate moving up the ranks more-so. If it's important to you to be a diamond player and you don't want to spend months getting there, then buy 450 packs. You'll only have yourself to blame if having 2 of every card didn't let you win.
Super-duper-legendaries? I like them. Even really-good-rares. Most have a downside or are situational. But some are slightly op'd. Kind of. Since the game has very powerful removal, silence, polymorphs, freezes and direct damage available to every class, they're not that big of a problem. Some rares are too good, some legendaries are a must-take at "we all have heaps of cards now" level of play. It's a CCG. They're like that.
But that's it. P2W? Not really. Your rank has very little to do with your skill. It's just a card bracket.
"How many cards have I unlocked and does it reflect my skill against others with similar cards?"
But on character design....... Bleh. The priest is pretty brokenly good, as well as hunter face-roll. They're being fixed. Hopefully. This is at crappy ranks, the broken gets smoothed out at higher card ranks.
So pay to be lazy, or be a priest or hunter and earn some gold. If I got a high rank after a couple of weeks of play in a fairly large CCG, I sort of wouldn't want to pay any money for it. It would mean that the game or the ranking system was broken. This seems fine. In another 3 weeks or so most of the mages clogging ranked will move on anyway, which is a pity really.....