My thoughts exactly. You don't need to know anything about CF in order to role-play. If you don't know where something is, well, role-play ignorance. If anything your character will seem more authentic than the rest of us, who magically know where all these areas are, what items do, what every other class's abilities are, etc.
Not being gear/percentage dependent in order to contribute to a group is also useful.
If we're thinking this newbie character is actually going to want to try PK, then his arial assassin will be much more gear dependent than the healer. Not that the healer is going to kill anyone. For healers, "trying PK", means "learning how to be attacked by someone and not die". Basically, neither the total newbie assassin nor the total newbie healer is going to kill anyone, but the assassin will probably end up dying more often. Hide and detect hidden are nice at the low ranks, but they don't match up as well at the hero ranks when compared to sanc, protective shield, free word of recall and gate.
The big caveat is that life as a healer will suck if you pick a deity that's hard to get empowered by.