Jarrod,
I just enjoy healing. Irl I'm a very motherly *and mother* person. I like taking care of my kids, guests, and family. So when I play an MMO the first job I head to is a healer. However, my character on Hyperion, the CON role is off limits until I can convince my husband to play after his studies >:(. So I'm a bit bummed. So I'm stuck playing my MRD, GLAD, LANC, and ARCH >_<; pug, con and thm are off limits to me. :(. Which makes me a sad sad panda :(.
It really depends on you as a person what role you like. And as far as needing a healer, depends on what you are doing. If you plan on tackling raids, then yeah you'll need one or two I think. And someone correct me on this, but I think is you level con to a certain point, in many quests you should be able to handle your own heals, I think, can someone verify his who has played more in depth than me?

