You make a good point there Orin, but not all galaxies at high Z look fully developed, I saw a really nice talk about high z galaxies at a conference, the slides are available here:
http://www.dur.ac.uk/cosmology06/talks/stockton.pdf
This was really cool work, it was the morphologies and ages of galaxies at z=1.5-2.5. Most of the galaxies they found were spiral like, but they were much too small, like 10 or 20 times smaller than spirals now. That much is ok, its kind of what you expect in Lambda CDM models, what was really interesting is the ages of the galaxies, these galaxies which are being seen as they were 10 Billion years ago have ages at that time of at least 2 Billion years. So they must have formed all of their stars in the first 2 Billion years after the BB and then sat there passively for the next 2 Billion years.
Now this kind of information is really cool because it allows you to compare computer simulations of the galaxies and the actual Universe. It turns out that is not actually unexpected to see this situation, the galaxies he picked are ones that are most highly clustered, ones that one day will become the giant ellipticals in the centres of galaxy clusters, and the galaxies he looked at do look like you could merge many of them together to get the big ellipticals you see today.
The other thing is that we are limited to looking at brightish things in the distant Universe which forces us generally to look at very large fully developed objects, these may be uncommon at that point in time but appear to be purely because thats all we can see.
The point about the CMB radiation echo is a common one because someone decided to call it such, even though it has nothing to do with echoes. The CMB radiation is simply the light given off just as the Universe cooled down enough after the BB (because of the expansion) so that protons and electrons could combine to form hydrogen. Before this point the Universe was ionised, so any light that was emitted would instantly be absorbed by a free electron and then re-emitted in another direction, so the Universe was opaque.
As far as I know there is no currently understood route to allow photons to decay, it may be possible for Protons to decay, but the lifespan of that cant be less than many Billions of years due to experimental limits.
Many astronomers have problems with many things in astronomy. Essentially none have problems with the Big Bang, if you ask them what makes them uncomfortable its usually Dark Energy or Dark Matter. It tends to be that people are uncomfortable with BB on deeply held religious grounds, but when you work in the field you see that there is nothing even remotely close to being able to match observations as well as the BB. As a species we need to get over ourselves and accept the Universe is not here for our benefit.
