On your point 1, the intensity of the background does not become infinite because, in a recycling type universe (static model), the photons have to degrade to 'paeps' (as Paul calls them) as well. In fact the amount of energy lost from paeps has to equal the energy lost from photons.Originally Posted by Nereid
On point 2, we also take note that the total quantity of radiation in a static model is constant. We know the rate at which stars emit light into space (approximately). We also know that the largest pool of photon energy is in the CMBR. If we apply the tired light redshift against the CMBR radiation, we find that the two rates are equal, as expected.
On point 3, my explanation would go over too much to my model. But basically, if paeps are also degrading to photons, then we have another background of very long wavelength radiation which interacts with matter and generates the CMBR. I'll leave it to others whether this is getting too much off Paul's model.
Point 4 relates back to point 2. What goes in must come out.
The questions are difficult and not to be solved in a day.