Finally got some time to sort out the Scoundrel issues.
The Sage healer never presented a problem - as a long range class I just park them at the edge of the fight and reposition if needed with the follow key. Nothing special is needed for their heals as well as even if they receive a DPS command during a heal they will continue on with the heal. Same with a channelled ability I believe.

The Scoundrel was the problem character. I wanted the Scoundrel to be a close range class which means a follow command is sent after each DPS command. Luckily all the Scoundrel abilities are instant (so far). The problem came to healing as even though they would continue a started heal if given a DPS command the resulting follow command would break the cast on the heal.

With some research I found this:
Key Map State Action
and
Action Timer
So now when a heal is sent the DPS rotation Key Map is disabled only for the Scoundrel for a certain amount of time. That is 2 seconds for a normal heal and 3 seconds for a channelled heal (only have those two at the moment).

It took some figuring out but I got it working. Basically I have a two step action to fire the heal:
Step 1
- Target the healee
- Keymap State Action - turn off DPS keymap for Scoundrel (no timer set)
Step 2
- Cast Heal
- Keymap State Action - turn on DPS keymap for Scoundrel with a timer set for the heal time.

So far this is working very well although I only got about 30 minutes to test last night after setting it up.

This isn't a very modular solution as requires calling to the specific character and the Action Target Group method is more flexible but this was relatively simple to do.

New Pastebin with these changes.