There is no drawbacks in using any ORM with Caliburn since they are two strategy working to solve different problems. And as a personal consideration are both great.
Here is a WPF example that uses Caliburn (not micro), Nhibernate, and Windsor. Not exactly the same situation but it might give a clue as to how session management is being handled.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.