You don't have to do anything like that if you don't want to. You can make a macro to automatically switch what action is in what action slot.

For example:

/crosshotbar action "Chaos Thrust" 1 16

The first number is the crosshotbar and the second number is the slot. You then just have to create two macros to cycle between pvp and pve actions.

/crosshotbar action "Purify" 1 16 would change the 16th slot of the first bar to Purify while the first macro line would change it to Chaos Thrust.