making a decent guardian is easy. making one that does damage and functions confidently as main heal takes a little more fg.
you can go ee weapon, heal mastery armor, stat charm
or ee weapon, ee armor, hm charm,
but it won't work if your heal charms arent boss.
and yes i think you wanna go all int. base int probably won't cut it if you are main healer
could be wrong, i haven't played that class in a while and the game has changed a lot since that time.
you might be better off building a different kind of setup, as samurai won't be able to use many of those guardian builds. but pally will. then monk will ruin your whole setup.