Why don't I have a custom title by now?!
For new monsters, the only reason to put in was to give more variety (I think I've added have a pretty decent quality and fit well). Doom has only three human-type monsters, I think this is very poor for a map set in the earth. Perhaps the problem is the way I've added some monsters, using random spawners for each class, for example, the zombieman class spawns three type of derived monsters, rifle zombie, pistol zombie and chainsaw zombie. The same happens with ShotgunGuy, ChaingunGuy and Imp. I can fix it.
That's a good idea, actually. Contrarily to randomizing replacers used to play in "normal" maps, here the entire level is built around this randomness. Though you should probably use "static" (non-random) monsters in some places to fine-tune gameplay.
Be wary about the superzombies, though. (I mean, zombies with BFG, railguns, rocket launchers, etc.) They're hard to use well.
Returning to the map, I saw that someone told me it was too brown, it is true, but I decided to use only doom II textures, I think has a decent set, but 80% is brown. Also like the Quake style that gives the brown.
No new textures, or no new texture patches? Did you at least use TEXTURES or whatever to composite things like these "DOOM" car plates, or are they built out entirely out of super-tiny linedefs?