http://tenhou.net/0/?log=2016032201gm-0009-0000-d166e1ec&tw=1

East 1:
	-Some tile efficiency issues. Major one is at step 7; you throw out the 9p and keep the 4-sou. It's faster to keep a closed wait (7-pin, 9-pin) and draw one tile (8-pin) to complete a sequence, than to have to draw two more tiles to complete anything for the 4-sou you kept. You were able to go for tanyao, but your hand could've progressed relatively faster and been worth more if you kept it closed.

	-Step 13: You went on the offense after C called riichi, when you should've been defending. Your hand is barely worth 2k, it's not worth fighting for when you had safe tiles you could've discarded. 1-man and 3-man were both very dangerous considering they were in close proximity to the dora and very few tiles around them were discarded. A also appears to be going for honitsu.

East 2:
	-Step 1: You keep the 8-pin after you had already discarded the 9-pin. Drawing 7-pin could have possibly put you into furiten, so be careful.
	-Step 11: You throw out 1-sou instead of 3-sou. You would've had a two-way wait on 2-sou and 4-sou if you discarded the 3.

East 3:
	-Step 4: You discard your xia pair and keep 1-man. This slows down your hand. 1-man is a useless tile to hold onto when you have 3-4-5-5 man. You end up discarding it later anyway.

	-Step 8: You discard 9-man and also the potential of 7-8-9 man sequence. You should've threw out 6-pin since it's not connecting to anything, not to mention D called on three 7-pin already, limiting your possibilities even further.

	-Step 9: You throw out 9-sou instead of 6-pin. You get rid of the chance of completing your 7-8-9 sou sequence.

East 4-1:
	-Step 11: Good move here. You throw out the 5-man early and keep xia, a potential safe tile. This is invaluable in the case someone calls riichi.

	-Step 14: You should be very careful following up with riichi against the dealer because they get a 1.5x bonus for winning a hand. If you deal in, chances are it will hurt. Also keep in mind you have 5 winning tiles left here, which is barely better than a closed wait.

East 4-2:
	-Step 5: You called kan here. Why? It's not the best move since you were aleady in tenpai, and this sets you back to 1-shanten. You should've called riichi since it was early in the round. Even if you were gambling on the possibility the dora indicator be 6-sou, you should've prioritized earning enough points to keep you alive. A tsumo could kill you at this point.

	-Step 10: You wait a turn before calling riichi. Don't wait. Your opponents could've progressed their hands in the meantime.

South 1:
	-Step 10: I would've called riichi here. There are no 6-sou in the pond and it's still fairly early. Closed waits on middle tiles aren't ideal but you'll need to push to get a chance at at least 3rd.

South 2:
	-Step 8: This was somewhat risky but acceptable considering it was your last dealer round. Could've ended up in furiten if you drew a terminal, so I wouldn't advise doing this in normal play.

South 3:
	-Good call. You needed a big hand to catch up to 3rd. Your starting hand was quite a stretch from chinitsu but you pulled it off.

tl;dr:
-Play more defensively when the situation calls for it. Let others be the ones to deal in if you can't finish your hand safely. The first mangan you got hit by could've easily been avoided. If you have a big hand you want to push for that can put you at a huge advantage, go for it. It's about balancing risk and reward.
-Work on tile efficiency. Keep an eye on what tiles connect to each other, which sets have the greatest chance of being completed, and also calls anyone else makes.
-You have a tendency to keep middle tiles even when they don't connect to anything and throw out closed waits. This will slow down your hand greatly. I know the temptation to keep middle tiles, but there's no guarantee you'll get a better wait.
-Take a quick glance every once in a while at your opponents' discards. There's new information coming in after every discard. Use it to your advantage. Keep an eye out for opponents that seem to avoid putting down a certain suit, or terminals/middle/honor tiles.