Yes, the flag is sacred and without the men who fought under that flag there would be no first amendment.
The flag itself isn't sacred, the sacrifice of those men who gave their lives for our freedom is sacred. They didn't give their lives for a flag, they died for us and our principles. I think the real things that represents this country is our character. Our devotion to free people around the world is what this counrty stands for not a symbol (flag, eagle, or whatever).
The flag stands for our freedoms and principles.
And to ban burning it would be spitting on those freedoms and principles.
But burning it does that too.
Not arguing that, but I find the former to be a worse affront. A freedom has to exist in the first place in order for it to be spit upon.