Tempo Razormaw is always strong - Only other mistake was not testing secrets. Counterspell or mana bind(in this case) really could have been bad. By the end with the way your deck was developing, against his, it probably would have been very difficult to win. Moral of the story here though, always test for secrets! That wolf really swung the game hard for him too. That deck could use some more cards to train out bigger, like tracking or something like that. Keep at it man, and always test for those secrets and make sure you're keeping a dominant board! (more minions > less minions, and razormaws can be freaking scary)
From my point of view, your only mistake is going face too greedy. Trade 3/2 into 4/3 is good most of times, and in this case that play could save you. I don't blame you for not knowing about his removal, but in that case his removal was more punishing than it could be. But, anyway, your opponent had way batter hand than you, so you'd probably lose that game anyway.
I think turn 6 you should've used hunter's mark for the grizzly, then flanking strike that. Kill the Scalehide with your 2/3 Razorfen. Would've allowed you to have the wolf and keep your Razorfen instead of sacrificing it to kill the grizzly. I would've played the Sunwalker over the Green jelly turn 7 and used the Faerie Dragon to trade with the Mana Wyrm. Never wanna leave those up. Fighting for board control and going face when you need to is probably the best thing to do. The earlier choices may have saved you.
Well, to start off, the opponent's mulligan was so bad, like beyond bad lol ... but thats just an observation. Lets continue.
T1: i would have probably played Jeweled Macaw; it could have potentially backfired, if the opponent was feeling risky and played that Sorc Apprentice into it instead of pinging macaw, but 1) you dont know what he has, its easy to assume he would ping it (and most players would) and sacrificing a 1/1 instead of 2/1 is better and 2) you would get a card back, which could have gave you a possibly better play for one of your next turns (that would be the main reason for me to play it over the murloc). In the end, either play was fine, but i felt like explaining my train of thoughts behind this seemingly easy turn :)
T5: This turn was a bit tricky, i would have probably gone Shimmering Courser solely to have a better minion on the board and also cause the 1/1 token would not force a ping from the opponent this time, since his minion can trade into it and survive, being no less annoying than it was last turn. So your play essentially gave you a 2/3 minion and didnt change the board state. Ponny would give you a 3/3 minion. But in the future, that extra token might have forced at least a hero power out of your opponent or something more, here it did literally nothing. Small thing, but small advantages do add up :)
T6: i think this turn was a mistake from you. You already knew it was not a Mirror Entity, nor Explosive Runes (even tho that one would have been perfect now), so you should have played the taunt. Wasting spells to check for Counterspell is a waste of tempo and your board. By developing Sunwalker you give yourself more options, while not rly losing anything. Also, why would you want to give him Flanking Strike over Hunters Mark? You dont have any big minions, so its use would have been worse than the Strike's.
T7: you are screwed on the board, you have no way to come back, you cannot afford to hold onto minions to squeeze every bit of value out of them, no way ... your best play was probably Sunwalker (since you didnt know he had Arcane Explosion, so he would have to trade two minions and hero power into it); or at very least play the 3/2 as well. The 2 dmg face at this point was useless, you are not smorcing him down, you will die first. The Shooting Star topdeck was very unlucky, but it wouldnt be "that" bad, if you played Sunwalker, it wouldnt do that much for him and could have separated the turns where he would play Shooting Star and Arcane Explosion, so the Ooze wouldnt get sniped right away.
T8: im not sure if you intended this turn as a hail mary to bait him go face and leave your minions up, but it almost worked rofl ...
T9: this is where you should have continued with the plan (if you had it), and trade into Raid leader with the Ponny. You would have two 3/4 taunts and your opponent would have only two 3/3s and an 8/8. So if he didnt have a spell to buff mana wyrm, he wouldnt have lethal (btw he would have it, if he didnt misplay that one point of attack on his T6) :) So if he didnt have a spell, you could have finally(!) played Sunwalker and mby stall for one more turn. Could have been very unlikely, but a possible victory for you.