It shouldn't be that hard to go through. If you're using Eclipse just go to the World class and find the source to the playEvent() method. Then just highlight the method name and right-click and select Call Hierarchy. That will show you all the places the method is called from. I just did that and there is only about 30 places, so would only take about 10 minutes to just go down the calls and see all the ints.
In fact for "fun" I just did it:
playDispenseSound 1000 (default), 1001 (fail), 1002 (projectile), 1004 (fireworks), or 1018 (fire charge)
ItemEnderEye.onItemRightClick 1003
BlockDoor.onNeighborChanged and blockActivated and toggleDoor1005 (iron door opening), 1006 (non-iron doors opening), 1011 (iron door closing), 1012 (non-iron door closing)
BlookFenceGate.onNeighborChanged and blockActivated1008 (if powered), 1014 (not powered)
World.extinguishFire 1009
ItemRecord.onItemUse and dropRecord 1010
AIFireBallAttack.updateTask 1015, 1016, 1018 (as the attack progresses
dragon.phase.PhaseStrafePlayer 1017
EntityAIBreakDoor 1019 (randomly about once per second, 1021 if door breaks (in Hard mode).
EntityWither.updateAITasks 1022 (something to do with destroying blocks?)
EntityWither 1023 (explosion occurred)
launchWitherSkull 1024
EntityBat.updateAITasks 1025 (when leaves hanging position)
EntityZombie.onKillEntity 1026
EntityZombieVillager.finishConversion 1027
EntityDragon.onDeathUpdate 1028
BlockAnvil.onBroken 1029
ContainerRepair.onTake 1029 or 1030 depending on anvil repair result
BlockAnvil.onEndFalling 1031
EntityPlayerMP.changeDimension 1032
BlockChorusFlower.placeGrownFlower 1033
BlockChorusFlower.placeDeadFlower 1034
brewPotions 1035
BlockTrapDoor.playSound 1036 (iron door open), 1037 (iron door close), 1007 (non-iron door open), 1013 (non-iron door close)
ItemEnderEye 1038
spawnDispenseParticles 2000
Various methods that destroy blocks 2001
EntityXPBottle.onImpact 2002
EntityEnderEye.onUpdate 2003
updateSpawner 2004
dispenceStack also ItemDye.onItemUse 2005
EntityDragonFireball.onImpact 2006
EntityPotion.onImpact 2007 if instant effect, 2002 otherwise
DragonFightManager generateGateway 3000
DragonSpawnManager.process 3001
I think that should be about all of them. I did it pretty fast so you might want to double check any that you're actually planning to use.