The Question and Answer section for A Farewell to Arms is a great resource to ask questions, find answers, and discuss the novel.
I wouldn't say that Henry is unpatriotic, as he certainly fulfills his patriotic duty. He does, however, lack Gino's commitment to the cause. Gino believes his involvement has to mean something..... that they haven't fought in vein. Henry fights...
Rinaldi is a surgeon, he and Catherine work together at the hospital. He is also the man who introduces Catherine and Frederic Henry.
What chapter are you referring to?