After thinking about this for some additional time and reading Kerrilyn's earlier post on the matter as well as having a lengthy discussion with 2 people who tend to play healers in our group I came to a few conclusions. The current system for healing focused characters feel static both in the diversity of actions during combat as well as the build/diversity. Healing is safe, there is little variation in it and it is a resource which gradually gets drained throughout the adventuring day. This has some positive aspects as it gives a sense of tension when they are running low on resources and at the same time every encounter becomes important in trying to reduce the resources spent.
Unfortunately, the straight up mechanics of most healing effects make them dull and both healers did express that they sometimes just felt like walking medkits for the rest of the party.
1. A general review of the cure spells for the divine spell casters. They are definitely on the low-end powerwise until you reach the Heal spell. If you can use your action and not even negate the damage a fighter takes from an opposing fighter in 1 round despite using your highest level spell slot is a problem in itself.
2. Diversify the different ways of healing. Heals which linger for several rounds at a lower pace, quick 1-2 action heals which can be used in an emergency. A feat which adds a temporary hp-buffer to yourself if you cast a cure spell on someone else?
3. Shamelessly stolen from Kerrilyn's post on the matter but healing spells which add other effects for a short time after the heal. Maybe even a heal which has an extra effect if the receiving target took damage during the last round? Heals which affect everything in a line (including enemies?). An additional effect if someone was recently crit? There are alot of possibilities and it would reward using the right heal at the right time and location.
4. If there are warlord type classes or archetypes then add ways for them to give people temporary hp as their ways of healing. Fits the theme of "inspirational leader" and still doesn't give some unexplained healing effect lore-wise to the world.
5. One point I've seen raised is the balance factor where a party with a healer would be more effective than one without. I can't see a major problem with this in itself, after all a party with an arcane caster is usually more powerful than a party without one. The problem which we should put effort into should rather be to turn the healing role into a more active and diversified role where people can choose to create their characters in different ways and which hopefully would increase player satisfaction during the game.
5. Naturally healers must be able to do other things except heal but just a quick look at clerics and oracles does this pretty well in the current iteration in my opinion.
6. Add bandages and enable the heal skill to be a valuable skill for fighters or other non-healing classes for downtime healing. Potions could cover the need for in-combat healing. (Though that healing probably needs to be stronger as well, see my first point regarding the cure spells.)
I believe this would add more depth and enjoyment to that aspect of the game.