I hate fatal errors & crashes! Because I mess with my system

I do occasionally overdo it... and most times this works for me... usually it's a second-to-last resort though, as it can take some time: (My last resort is uninstalling and then re-installing Wow...)
1. Back-up your interface & wtf files
2. Run WoW's repair tool, resetting everything to default
3. Load WoW, don't panic-- you'll restore your customizations in a minute...
4. Make sure that it runs without crashing... One time, I found that I needed to replace my video card when the program crashed at this point--if it crashes with defaults and no AddOns, you might have developed a problem with your hardware...
5. Exit WoW
6. Copy the config.wtf file back into the World of Warcraft/WTF folder... you should have a folder named Account and a config.wtf file... this config file will configure your system settings back to before...
7. Load WoW again. Now your screen should look more familiar... Log into a few characters to be sure it all runs smooth--it should at this point...
8. I usually make another backup set at this point--since I know it's all repaired, it's easy to backtrack to here if I have a backup. (Probably an unnecessary step but it makes me feel better.

)
9. Reload your addons. You probably should load them one-by-one... I'm usually too impatient at this point and tend to put in the ones that I've had the longest, leaving out the newer ones.
10. Reload WoW, logging into each of your characters. Don't bother to configure the AddOns...
11. Log off again and copy specific wtf files:
For Addons like Dominos, that you've spent a good deal of time configuring, dip back into your original backup wtf file and copy those back to where they belong. Just pay attention to the file paths... I don't copy all the wtf files--most of them are easy enough to configure in-game and my assumption at this point is that if it's running smoothly, that the conflict was buried somewhere in those layers of wtf files...
I hope this all helps... Good luck!
Added: sorry--just read back that you haven't had any problems since your file clean-up yesterday-- hope you're still problem free!
If you're one to experiment with lots of different AddOns, they're bound to muddle up your wtf files over time.
Here's a nifty little solution to keep your files nice and neat... word of caution though--it's a little wonky at times and has this issue of freezing up. I haven't found another like it though, and I think it's so darn useful that I put up with it's little ((ahem)) issues... You run it outside of Wow...