I'm sure it was said, but also play the job as you want to. If you aren't doing endgame content, its a LOT more flexible on how you play.
You Can, just spam cure 1, if you want, and you wouldn't get yelled at. It is more efficient to wait, DPS and use Cure 2 and regen, yes, but you won't get harassed for it.

In lower person content, lets say Duo Eureka as heal/tank, i found i would charge Assize with Lilies before the assize update with the latest patch.
Lilies Can help, but its not something you rely on, which is why most people say don't bother with them. Even if they made it so you could store, and then Choose to activate, that would be better.

All healers start with a DPS spell, that should be an indication of their capability. Yes, their role is to keep the party alive, a "good" healer, will help kill monsters faster, negating the need for extra healing.

Don't get discouraged, healers are fun to play and rewarding. Some situations call for specific things, but for most normal content, play it how you feel comfortable.