I pity you, man. I got the exact same problem. ESF 1.2 won't run, huh? Well, the textures aren't the ones screwing it up. It's something else. A file called recoverjump.wav. It's crashing the game. If you can find it somewhere, just copy it in every folder you can and it will work. Or try to update Half Life.
P.S. If you do find it, PLEASE send it to me! Contact me via private message for the email.
The key is NOT using steam. It's updating half life. The files won't hurt anything, you're right about that, but steam is NOT neccessary for playing esf. It's neccessary for playing online, but not offline with the bots. I know this because I have tried it myself and it works. ESF still technically runs on WON, offline and on LAN, and that's the way it should be. That's my opinion. So, Neoblast SSJ, don't use steam, update half life to 188.8.131.52 and it will work 200%!
ESF is not supported without Steam because it is illiegal otherwise. dan_esf_fanatic if you continue to spread propoganda about non-steam use you will recieve warnings untill you are banned. Am I clear?