Hi stwrsfan1!!
Once you move on from a role you cannot go back unless you reset the adventures.
Other than the rapid advancement in levels that one can make by switching roles, I'm not certain that there would be that much advantage to doing so once you have achieved a role such as Zen-Master. Of course, you can always try it out for a while and see if you agree. If you like the changes, continue playing. If not, reload your previous game!
Wyv