Perhaps it is that the United States is a relatively young country, and composed of the descendants of immigrants from many different places that makes it so conscious of a need to have some kind of declaration or pledge. The richness of 'unity in diversity' is a good thing. Certainly older countries that I know of, don't find this declaration necessary, probably because ethnically they are a unity already. Loyalty is an accepted fact - a given - that is never questioned, so the premise on which older countries are basing themselves is quite different.
To illustrate what I mean, In my own case, coming from a country whose language and roots go back more than 2,000 years it would be considered superfluous to have such a pledge. Our identity as a nation is clear and stable without a daily reminder as to where we stand and what is expected of us. Also our history, landscape, ancient and modern momuments are a constant reminder of the loyalty due to who and what we are.
So I appreciate in America's case that a declaration of loyalty can be desirable as a cohering factor. However, I would query if the daily repetition of the pledge, however binding it may seem, could have a familiarising effect that 'numbs' it and renders less valuable the intention behind it would want it to be. The old adage that 'Familiarity breeds Contempt' could come into play, and that, ultimately, would be self-defeating.
Perhaps there is a case for making it particularly meaningful by using it on special occasions. This however is just the view of someone looking in from the outside. It is only an opinion - perhaps something to think about, or even dismiss, but hopefully not out of hand.
As to the actual terms of the pledge, I would comment that the flag is only a symbol. It is what it stands for that is the kernal and core of the matter. This is what is really important. I would also imagine that it is going to be problematic for those who are non-Theists/Deists to subscribe to the term 'under God', especially in the light of the Founding Fathers views and the Treaty of Tripoli.
On the other hand, for believers the country is in any event 'under God'. The phrase is therefore superfluous on the one hand and possibly even divisive on the other, which seems to run counter to the whole purpose of the pledge. This however is one for Americans to sort out for themselves.
I would however suggest a different order of the wording as well, to fit what I perceive as the greater significance of the pledge:
"I pledge allegiance to the Republic of the United States of America of which this revered flag stands is an honoured symbol;
One nation Indivisible in its Unity; with Liberty and Justice for all."
Sadly, under the present administration the denial of Habeas Corpus in overseas territories on the shallow pretext that it does not apply there, and the special rendition flights make the last - and very important phrase - ring quite hollow. What a shame that a great country should deny anywhere what it so proudly pledges itself to in its home territory.
To my mind the pledge, even as it currently stands, should be the catalyst for Americans to be doing something about the proxy torturing and denial of trial and due process of law that the administration is engaging in. America's honour is really at stake here. But I am now way off
Still, to try to bring the posting back into line, a pledge is something which demands honouring, without any reservation of evasion, before whatever deity one worships, or as an expression of one's personal integrity. All the more so, perhaps, if one is a believer in the bible and all it contains, especially the Christian message.
Just some thoughts from an oursider looking in.