You have to take care with a MW. You can go OOM because of the instant casts in a large fight and if you are constantly changing you channeled targets. Carry mana potions, many people of them. And be mindful officials where the healing hut is so you can run in there to get full mana.
MW are fun. There is no doubt. But they are vulnerable compared to other healers. You have to know when to RUN.
Have a marvelous day!