Great guide/advise. I will be coming back to this offen on my track to 50.
I know that you didnt mention addons, but I would suggest HealBuddy or one like it. It does 2 key things, give you a color-coded arrow for party member that needs to be healed and will craft a macro to target the member with lowest health( for single target healing).
The arrow alone is worth it, to help keep track of where to send your next heal.