PvZ Plat, unsure which aspect to improve

I probably could have: 1) scouted earlier? 2) tried to pressure the zerg player? 3) made more concerted efforts with the air attacks? 4) not screwed around with air at all. 5) something else?

I'm confident I was totally hosed by the time I was screwing around with carriers on the island at the end, but in retrospect I probably could've done something more constructive; I'm just not sure what.

I just don't feel as though I know what I should have learned from that game.

http://replayfu.com/r/LH9Jgn