It is Mac-friendly. If your game is still crashing then try pulling out the folder called "The Sims 3" from Documents (it will be within a folder called Electronic Arts) and leave it on your desktop. Start the game. The game will regenerate a fresh setup (you can always get your old one back because it's still on your desktop. Try playing a new game with the fresh setup. If that works then you can assume there is something corrupted or unhappy in the old folder.
Perhaps you are having hardware problems. The flashing and distortion you described happened to quite a lot of people about a year ago. The latest patch (1.63) plus resetting the RAM resolved crashing and graphics issues for many Mac simmers, which is why I suggested it. However it's possible that your situation is being affected by something else. If you have an Apple Store nearby, you could consult the staff there. I don't think it is the hardware, though - I think it is the game, because it is also freezing and crashing which suggests the game isn't working properly.
Caspin
