i suggest you keep separate buttons for the healing. you want your heals to heal the tank and not to match what the tank is doing. its a lot harder to do this as opposed to having two different classes dps.

healing is situational, and you should save your mana for that. using moonfire, wrath, or whatever other spells in tandem with warrior attacks will probably mean your healer will be OOM by the time you need it to actually do what you want it to do... which is heal. constantly reapplying moonfire is super mana inefficient, as is casting heals when you're pretty full on health. there is no reason to have to match your healing with any of the warriors attacks. none.

if you're just two-manning it, then i would add a few attack spells (maybe just wrath and moonfire) with some warrior attacks. rend+moonfire and heroic strike+wrath. but dont kill your mana on these spells. remember your resto druid is still... resto and needs to heal.