All very true. This brings us to the point of what kind of zombies we are discussing.
If we assume regular NOTLD type, then it is possible for them to rot, but not at fast rate.
As for DOTD Zeds, rotting does not come into play unless injury occurs, as Zeds don't regenerate.
As for RE Zeds, no rotting would take place due to the fact they are not entirely dead as we know and they regenerate.
Same goes for ROTLD which has been shown to cause sporadic changes in zombie pheno-and genotypes.
Available data seems to suggest the zombie virus produces a toxin which inhibits bacterial growth.
If the normal decomposition cycle was occurring in zombies, most of them would be rendered immobile in a matter of days. The bacteria that normally live in the human digestive system begin breaking down the body within moments of death. The main byproduct of this is gas, which causes the body to distend. If bacterial decomposition was active in the undead ( allowing for temperature and weather variations), most zombies would either burst or be rendered immobile by distention within 2-3 days.
The maggot factor is most likely do to decaying flesh/blood of victims remaining on the zombies.
As for removable limbs, this would be due more to the lack of cellular regeneration. Muscle is strained every time it's used, and since the undead are not biologically alive, joint wear would eventually lead to loss of limbs. The most likely scenario being that zombies would eventually fall apart due to wear and tear.
Yes, a Zombie would eventually rot to the point where it could no longer move, and would eventually become just a skeleton. But, the rate of decomposition would depend on the amount of moisture that the corpse retained, and it would have to be in liquid form. For example, if there were to be an outbreak of undead zombies (I'm being that specific for a reason. If the outbreak were caused by something like the Rage virus, then they would not decompose) during the summer, then each would have an average un-life span of about 3 weeks to a month. If an outbreak were to occur during winter; however, the water inside the zombies carcass would freeze, allowing it to survive, hypothetically, for the entire winter with out rotting away.
This is where the theory about the virus being toxic to normal bacteria comes into play. If you presume that normal decomposition is taking place, I'd have to seriously argue that a zombie would be rendered immobile within days in summer conditions. Skin slip, bloating, distention, these things would have a dramatic effect on a mobile body.
As for freezing, that's based more off of the fact that the undead are "cold blooded", ie they're bodies are at room temperature. While this does increase the risk of zombies "surviving" longer, it also means in a cold climate (with average temps below zero), you'd have a period of time where zombies were immobile. That's why I plan on heading as far North as possible.
Well either way think of it like this you'd come out of your hidey-hole to find a world hardened and you’d miss out on forming alliances. So you could but only if you want to be a outcast with no land no power and no friends.