Hey Grey.
Each group tab contains the list of all turrets. If you don't want one or more turrets to fire as part or a group, you can click the X in the top left of the turret box to disable it in that group.
When you target a ship you can select one of it's systems as a sub-target. If a turret has line of sight to the target ship, but not to the sub-target (for example the sub-target is on the other side of the ship), then that is a partial lock.
When setting a group to auto fire, On Full means turrets only fire when they have line of sight to the sub-target and On Partial means that the turrets will fire as long as they have line of sight to the target.
I don't disagree in regards to the armor damage indicator colours, green to red is much more obvious (even if it doesn't suit the colour scheme). Nothing is set in stone, so it's entirely possible I will change the armor damage indicators back to green/red before release.
Thanks for your continued support man.