I've tried similar, but found that the collision is way to sticky with the multiplayer physics to be usable. Perhaps I was giving it the wrong properties, but I'll say it was borderline unusable, at least as a door.
Looks good... but I'm with the nay-sayers who think you should change the name. The stargate mod just got C&D'd, and there's no reason it won't happen to you. I don't think any judge in 'court' would be moved by the "OMG IT'S JUST A WORD" defence (there is NO legal basis for that). It's just a...
I doubt it, but you won't be able to interact with them like you would in HL2:SP. The physics with ragdolls feels leggy when you run into and touch them in HL2:dm
the textures look great so far. The map is... a vehicle for textures, so probably isn't worth comment. The hud: are the 2 shots supposed to be different? Is the "no damage/not being threatened" part of the HUD? If the 2 shots have different graphics, you may want to think about using more then...
Looks great. My only question is about those towers in the background of shot #3. They look like they're supports more then antennas, but they have nothing on top. It's nit-picky, but when something looks good, it's worth picking the nits.
The snow mobiles look fun. I'm not sure what the role of those big tankers is: maybe you escort them, and they're basically enormous bombs on wheels. That might be pretty cool, actually.
I'm not sure about those models specifically, but they would need to have an "off" skin. You can open the model in HLMV to see all the skins, and put in the corrosponding number of the one you want in the model in hammer. Keep in mind that they very well may not have an off skin, though.
Then you better like lag, because that's what they're designed to prevent. I don't think VALVe would make a crappier version of something they already had if it was unnecessary.
Remake the rock blocking the tunnel as a prop_static. You can do this in the XSI modtool if you don't have a 3D package. I'm guessing that the complex BSP in the rock is making things go insane somehow.
I guess before going through that trouble, save a copy of the map without the rock annd...