Minecraft crashing on Mac OS with Java 8 - any fixes?
IIRC, Minecraft is hard coded to use Java 1.6 (or it might have been hard coded to only use Apple Java, can't 100% recall). 

The way I have combatted this for some time is to launch Minecraft from Terminal.app using:

java -jar /Applications/Minecraft.app/Contents/Resources/Java/Bootstrap.jar


I think I recall Minecraft developer Dinnerbone suggesting that Minecraft 1.9 would not pose restrictions on Java version.