It seems fairly well known at this point that anyone using 1.6.x can modify the amount of RAM a machine is using for Minecraft (by adjusting -Xmx1G in Profile: JVM Arguments, 1G being for 1 gig of RAM, etc).
But what other arguments can be applied? Is it possible to set any of the values which can be set in the options so that that property changes when the profile changes? I would especially like to change the difficulty for one profile to Peaceful while leaving it at Hard for others. Does anyone know how this can be done via JVM arguments or of any other way to do it?