So I found SOMEWHAT of a solution. It might not work for everyone, but it at least helped me get past the intro.
Validate your files on Steam. It doesn't matter if you already have, try it again. Usually one or two files are missing and if they are, that's a good thing.
NOW. Start up the game and try to progress past the padlock. It loaded for me just fine, and I was able to get the code and keep going.
SAVE RIGHT AFTER YOU GET THROUGH THE DOOR WITH THE PADLOCK. AS SOON AS YOU POSSIBLY CAN. DO IT DO IT DO IT.
And after that it should be smooth sailing throughout the game. A couple of crashes here and there, but due to the Half-Life code thingy, I don't think there's much the team can do about it.
So tl;dr - Validate, Progress, SAVE, profit.
Try it, hopefully that's the best solution out there.