1) You can hit H with your left pointer finger if you want, really. Try it a few times and see.
2) So, since the key that cycles through Escort ships doesn't do anything with not ships in escort list, have it cycle through all friendly capships, right? I mean, the fact that your escort list is empty should tell you that there are no escortable ships... And since the target next turret key doesn't do anything after the turrets are destroyed, it should target the next nearest hostile capship and begin cycling those turrets, right? The targetted ship changing should tell you that there's no turrets left....
3) Now, imagine a mission where you are not to attack a hostile unless it's attacking you. Now this key gets all jacked up, cause it looks like they are all attacking you unless you notice the threat indicator missing.