In regards to Match 4:
I very much disagree with your turn 2 play. You spend your entire turn playing arcane missiles and passing, and while it does get rid of his board, it doesn't really develop yours at all, plus it uses your mana very inefficiently. On top of that, you've effectively traded a card and 2 mana (missiles, the mana it took to cast it, and the mana you didn't use because you decided on that path) for 2 mana that he didn't even have to spend a card on.
There's a number of plays that would've been better. Coining out any of your three drops would have been better, since it develops your board and leaves you with a 2/3 mana wurm, plus the effect of whatever you play. Shattered sun Cleric is probably the one I would choose, since you get to have a 3/4 mana wyrm and a 3/2 SSC at end of turn. I'm unsure whether trading with the 1/1 is good or not. I would, but I tend to clear the board more than I should. Coining out an acolyte of pain to try and eat his 1/1 and any future 1/1s is also fine, but I think worse than SSC since it puts so much less pressure on your opponent. Just pinging his 1/1 would have been better as well, although worse than the minions.
One of the strengths of a card like arcane missiles is that it allows your to use your mana efficiently. Because it costs only 1 mana, you can fit it in on a turn where you would otherwise be wasting a mana crystal. On the other hand, those 3 drops are going to be pains to get out of your hand after turn 3... you want to play one on turn 2 and one on turn 3 to use your mana most efficiently.
The coin gets weaker as the game goes on, generally... you ended up not even using it! Coining out a 2 drop on turn 1 is the best use of it, coining out a 3 drop on turn 2 is the second best use, and so on... You could've pulled really far ahead with a strong turn 2, putting 2 strong minions on the board. That's an opportunity you just can't afford to pass up.