Panther is amazing. Once it's up passed lvl 15 it seems to keep aggro pretty well, and you can easily keep it alive being a healer (I would hope). Panther also will just give you combat advantage without having to lift a finger.
As someone who's pretty much solo'd 1-60 I can tell you that Healing Word is one of the most useful spells you have. Because of the charges, you can fling out a quick heal on yourself or anyone near without much effort involved. Group abilities are definitely nice, but single target heals are also very good in this game so…