A topic as fascinating as it is vast. The thoughts  and the questions you pose touch on so many aspects of life that one post cant do it justice. Some first thoughts:

In this day and age, Nepal is just a day's flight away. Our loved ones are one calling card or a Skype call away. We have the luxury of being able to spend two weeks a year in Nepal and the other fifty  in America. If we have become prisoners in paradise as you allude to, it is because we are prisoners of our thoughts and emotions. Luxury and nostalgia are our crimes. Our mind, not America, is our prison. At least that's how I see it.  

The way out, in my opinion, lies in striking a balance between the different cultures and contradictions that are a part of us. We need to come to terms with and embrace every part of our past.  The more colorful the identity you embrace, the richer your life. Think of it. Take Mr X. An Asian-American heterosexual male of Nepali parentage,  Hindu by birth,  agnostic by choice, politically liberal, socially moderate, fiscally conservative, internet savvy, technology mad, English speaking, momo loving, opposed to Maoism, intrigued by Buddhism, married to secularism, a pacifist who can pack a punch but never his lunch, medium built and burdened with lots of guilt, celebrates Dasain  with family in Nepal and Thanksgiving with his brother Gopal.  Happiness is the art of delicately balancing the push and pulls in ones life.  We all need to connect to the Mr X (or Y or Z) within us. When we are happy where we live is of less consequence. That might sound a bit preachy but it works as far as I can tell.

Dual citizenship will be a reality in most countries in the future if I were to make a guess. You might be able to fly from New York to Kathmandu in 6 hours some day at the rate technology is advancing. The differences between your own culture and the culture of the host country becomes less  meaningful  in a world connected that way. How about Labor day weekend in Kathmandu? Fly out Friday morning and return Monday night? Sick of your self-righteous  neighbor? Want to meditate on the foothills of the Shivapuri? Himal Air is offering a $500 round-trip getaway to Nepal this weekend!   Daydreaming? Sure. But we live in exponential times, today's dream will be tomorrow's reality (or at least the next decade's). Life expectancy is on the rise worldwide. You might easily live to be a hundred if the radiation from surfing Sajha.com all day on your laptop doesn't kill you by way of  testicular cancer.  Technology is brining the world closer and rapidly enabling us to experience being Nepali without being in Nepal. 

That said, everyone's personal circumstances are different and what is sauce for the goose many not be sauce for the gander. What Nepal means to me maybe different than what it means to the next guy. At the end of the day we each need to find our own answers.