Frank seems like a wonderful balance of being thoughtful, well-spoken, but also being a fighter. Just his dialogue in your exchange with him speaks volumes.
I've become quite attached to my three sheriff's deputies and their British friend. When Broken Silence is finished--and it will be finished before this year ends--I will miss them all greatly. There are short stories and other adventures for all of them involving the Doctor and others. But they won't be nearly as long as Broken Silence. They know that when the war is over, I'll be coming back to their story again and again because winning their war will ultimately help me win mine.
I've tried to make them as likable as possible but as real as possible as well. The three of them are wonderful but flawed, as most people are. I realized just right now that their flaws are linked into how they handle emotion. Because of his unique origins, one of them has bouts of powerful emotions and doesn't know how to handle them sometimes. Another doesn't want to feel emotion anymore. Another has spent much of his adult life hiding from his emotions because that's what was expected of him. He's now found that he can't hide from them any longer. The last one is so young and so unsure of himself that he's still trying to find his place in the world. He becomes so painfully and humorously awkward. None of them are related, but they might as well be.
All of them (including the British friend) display a level of bluntness I think is appropriate for their chosen profession. But like O'Neill (and I imagine Frank too), they are much more intelligent than most people would give them credit for. That's why I really want to get the story of their war right. I owe it to the all of them as I believe you feel like you owe it to Frank too.