Since you specifically posted you don't mind harsh criticism I'll just go ahead and be an ass.
Don't take this as an offense. It's just that the negative aspects of a map are way easier to spot and to comment on. When I post more negative things than positive ones here then this is due to me being lazy, not due to the map being crap!
(you should post the images you posted over at beyondunreal here too. I went from the pics for everything below)
The textures for the walls looks very washed out. Partly because they have nothing structural to them and partly, I guess because you compressed your lightmaps. Open the build options and change the lightmap compression from the compressed DXT3 to the uncompressed RGB. Contrary to what one might think this will even decrease the file-size of the map rather than increase it! That way you will get rid of the dodgy light color patches on the walls.
The new screenshot you posted over at beyondunreal looks a lot better already but you don't have to go that far. As it is now it looks more like a secret science facility, in my opinion, rather than an abandoned (and therefore probably oldfashioned looking!) hospital. You could make the walls have that horrible 70s yellow-green color on the bottom half and white on the upper half. A supposedly friendly combination of a very low saturated blue and white has a hospital vibe too. You can make alternative versions of those wall textures with brown stuff that leaked through the ceiling.
The lighting itself doesn't looks very impressive either. It looks like you just placed low-radius lights somewhere near the middle of the room to light it up somewhat so it looks dark but players can still see in it. Of course that'S a valid technique, but it shouldn't be the only method used to light the place up. What you simulate with this is refracted light coming from somewhere. E.g. if you switch on the light in your room the area under your table is lit quite a bit. In UnrealEd it would be a pitch black shadow down there because there is no refracted light. With no real lights at all anywhere there shouldn't even be the low illumination though! A few functional lights wouldn't break the abandoned hospital atmosphere in my opinion (especially since the computer works too. Try if a less saturated blue looks better, btw). Just a light every few rooms and have ti leak over into other rooms a bit. E.g. through the glass part of doors, under doors, through open doors, ... Use windows too! Even if the map takes place at night you can have a little light out there (maybe from a near-full-moon). This would light up the corridors with windows a bit and you can let light leak into adjacent rooms from there.
If you make some brighter lights you can play with sharper shadows too. Window blinds casting sharp shadows (maybe even onto a bit of dust hanging in the room to make it even mroe impressive looking) are pretty easy to make but they are always a bit of a "wow" effect in games.
I don't know the specifics for your project, but as a playable map for UT2004 it is way too cramped! Realistic indoor places are generally iffy in UT2004 because the players are small, fat dwarfs that run insanely fast and can jump pretty high. Of course all of this clashes with the realistic scaling of realistic rooms. I guess this is all good for your school project, but for a playable map its a fat minus point. You can try selecting everything in the map (draw a huge selection rectangle around it all) then go to Tools -> Map Scale and scale it up by the factor of 1.5. Just to see if it's better that way.
Now, not to be all negative.. This isn't the only thing that is positive about the map, but it's what springs to the eye: What I can see of the models looks very good. I'm sure they'll look even better with more pronounced, more focused, cleaner lighting. The old rule for drawings (shadows make objects look three-dimensional) applies to 3d art as well, to a certain degree.
Some suggestions for additional rooms:
Splinter Cell (I think it was Pandora Tomorrow) had a level where you start out in a kid's room which is dark and only lit by one of those lamps with the black cardboard rotating around it with cut-out dinosaurs that cast their "shadows" (ie, there light) on the walls. This looked very
impressive. If you can pull off something like that for a kid's room it would look both impressive and creepy. Easier to make but also cool: cut-out cardboard figures on the windows, which cast their shadows into the room. Like window colors (probably too modern) but with cardboard. If you like modeling you can also have a teddy bear sit on a bed somewhere.
You could have a stair way somewhere with huge glass double doors before it that are locked with a heavy chain. Making rooms players can see but not enter makes the level appear much larger than it really is. It makes it seem like the player is only in a part of a larger whole, which does exist (he can see it) but which he can't access. The suggestion of the butcher room is also great, but I don't know if that's the vibe you are going for. If you do something like that make sure you have a trail of smeared blood leading into the room (projector).
For corridors you should make the floors consist of this weird somewhat soft plastic stuff that looks and feels a bit like fluff in plastic. I'll be damned if I know the name... Anyway, it's a little shiney so it's an easy way to get in another cheap "wow" effect. Either make it a little shiney everywhere or make it broken up by straight seams where the next roll of the darn material starts or add even more breaks that looks like the fissures in dry earth to make it looks old and broken. If you go with old and broken, make it NOT shiney around the breaks. Looks even more impressive.
My verdict so far: I wouldn't want to play the map because it looks so small and cramped, but I can hardly hold that against you, can I, since it seems like it was part of your assignment. Visually, the models looks very good. The textures are too low-res but you are already working on that. The light looks a little too bland even for an abandoned hospital but you are working on that as well. So I guess it's shaping up quite nicely, even if it will probably remain a good looking (potentially very good looking) tech-demo rather than a really playable map.
You can circle that issue by making the map for a mod/game-mode that works well with cramped maps instead of releasing it for vanilla UT2004. The Y.A.R.M. (Yet Another Real-Life Mod) might be a good choice. Blue Moon Rising could work quite well too.
I'm downloading the map at the moment and I'll check it out in person when I get the time.