I would absolutely love to help, but unfortunately I don't have any other ideas than the things you've already tried. But if you're planning on holding out for someone who might possibly be able to fix it, I would suggest at least moving the file out of your saves folder for now, or deleting it altogether since you've uploaded a copy to Mediafire. Because as Pam said: corrupted files have a way of corrupting other files. It's best not to take the chance.
Another thing I would suggest, in addition to creating multiple saves under different names, is to regularly copy your entire save folder to a flash drive. Don't bother opening the folder up. Just copy the entire folder titled "Saves." If your files get corrupted, fixing it is as simple as deleting the old folder and then copying and pasting the one from your flash drive into your Sims 3 folder.
I've had file corruption that was so extreme and far reaching, that it would have wiped out a majority of my saves, including my most recent Dynasty attempt a couple of times now, had I not been doing this.