And, of course, weaponclip can be walked through but it blocks bullets.
Wrong, weapon_clip blocks players and bullets. It is not possible to create a shader that can be walked through yet stops bullets (Believe me, I've tried). Though I'm sure a few small tweaks to the games code would allow it.
Metal_Clip is pointless, it's more appropriate to make the metal itself have that property.
The reason you use clip instead of caulk within the map is because it doesn't block vis, whereas caulk does, which as previously mentioned results in the "Hall of Mirrors" effect.
Bot_clip and Missile_clip are for Quake 3.
In regards to the actual topic (The map); You need to work on detailing and making it less blocky. You should have worked on it some more before release, remember the "Random Dev Shots" thread is there for you to get C&C.