Well, not every area DOES have lockers, pipes barrels etc... But then, this isn't a defensive bunker anymore. The original level was set as a bunker on a beach, while the Axis had to protect documents in a locked down bunker, and the Alies had to steal them. But that was during a war. If you think about it, the plot of OD is that its no longer a war in the classic sense, more so a fight for survival. This entire battle could be taking place in a candy shop, it could be taking place in bay 7 of the local ASDA... Does that mean that those locations should only have Toys, or Food etc?
Of course, the original theme plays a huge part in it. But take your home as it is today, then wait over a hundred years and nuclear wars later, and you tell me would it all be as it is now? You will have people hunting for whatever they can use to survive, you will have people setting up homes and safe areas, you will have people storing all sorts of things in the most strange places.
But in answer to your question of it being "silly" to have lockers in a "defensive" bunker...? Well think about that. Those lockers could contain ammo, weapons, protective clothing? Would you like the people there to leg it up the hill to the changing room every time they shit themselves?
In relation to other items:
Floor/Floor damage - Yeah I agree. Its mostly down to perspective. With it being so close to the floor the tiles look REALLY odd, however I have been toying with changing it, but as yet my minds blank.
Lockers are shiney/bland - Totally agree, and will be making seperate "rusted/dirty" versions soon.
Physics Engine etc - Well, we wont have Crysis level shit, but I can tell you its gonna be COD4 level at least, as in if theres a tin can there, you can bet your arse you can shoot it around.