Oh yeah, I do overheal all the time too, mostly with Whispering Dawn, the reasoning behind it being that it's free healing that gives me some hands off time so that I can better DPS, but that's not something I'm going to tell someone else to do, so yes, I admit I was being unclear...
What I meant by "standing around or overhealing" is using GCD heals like Cure or Medica spells to heal the tank/group who don't need it.
And that's most of the time good enough, just re-applying your DoTs when you can and everyone should be pleased. Getting in Broil, Ruin II and Energy Drain casts are something you can start sneaking in once you feel confident enough and know what to expect.