Realistic, the word, is pretty loaded nowadays. The moment you use it, there's a fairy chance you'll have a dozen rabid anons jump on you for it. I prefer to say plausible.
I think the biggest reason I love this film is because Bruce's arc is inspiring. I was also against Blake being a Robin-type figure until I saw the finished product.
I believe Alfred's tears were more because he failed his own code, or "rules" if you will. His hinted backstory leads me to believe that he places a lot of value on loyalty and devotion...and he failed in a pretty big way.