I recommend some basic research into military things as a base for watching NuBSG. It gives a new perspective on a lot of the show - both the good and the bad. And this is because large segments of Seasons 1 and 2 belong to a subgenre called "military sci-fi". Interestingly, large sections of Stargate SG-1 are also military sci-fi.
For example, understanding of military things reveals why the large audience the show started out with amongst service personnel were upset with the Pegasus episode and its depiction of military personnel. That audience understood well that there is simply no way that a psychopath like Cain gets through the screening and testing to achieve any type of officer rank - much less flag rank.
Another example in the other direction is the appreciation service personnel have when the show depicts things like hangar deck operations (and get it reasonably right in a sci-fi context) or the planning behind an operation - and then showing the battle/operation unfolding according to the plan.
I know this is an old thread-I was just passing through---The thing with Cain that your comment on her not being fit, it made me think of, if pressed, what kind of "pull it out of your butt" answer RDM or Eick might give. So here goes: Cain is a Tauron, given the tight society the Taurons have with influencing officials to get favors done-Cain did something for say the Ha- LaTha and they got her the commission?
Being retired Army ,I agree that someone like Cain wouldn't make it through our officer candidate school and certainly not West Point (I leave out ROTC since there is no indication that such a thing exists in the bsg-verse)-she would crack under the forced pressure they put cadets through. She would get through an enlistment physical- it is not very thorough on the psych stuff is basically all self-admittal.
But then again, look at current events and this Paula Broadwell woman. She is a west point grad and a Lieutenant Colonel in the Army Reserves- having also had to serve 5 yrs on active duty after West Point. She clearly has some type of mental/emotional issues that could prove fatal in a command situation.