Our generation has forgotten the purpose and usefulness of symbols, and so we show disrespect to the symbol of our nation. The flag code is meant to instill a sense of respect for the founding principles of the Bill of Rights and the Constitution by showing respect for the symbol of those principles. It has also come to represent the sacrifice of those who have fought to preserve those ideals.
I don't agree with adding anything to the United States Flag. If you want to associate your group or ideas with those of the United States, just fly your flag along side the stars and stripes, not on top of or above it.
I do not like to see displays of disrespect for the flag because to me it means that person does not respect the principles of our nation. I just don't think spitting on or burning that symbol is a productive way to show displeasure with certain action, policies, or laws currently enacted in the country.
Do we as a country always live up to our founding principles? No, but you can protest and pursue changes without disrespecting the underlying principles that I think most people still believe in. It seems to me that most protesting occurs when people feel like the rights and values represented by the flag have been infringed so it doesn't make much sense to me to destroy the symbol of the very thing you are trying to protect under the pretense of exercising the very rights symbolized by the thing you destroyed.