You don't repair inventory items in the originals, that was a new feature introduced for Fallout 3. A great system, but I think it needs alot of tweaking for FO4. Maybe we'll see an improvement for F:NV? Who knows.
Your weapons can blow up in the originals though, but they are known as 'critical failures' and usually require your character to be very unlucky or unskilled with the weapon he/she is attempting to use. I would like to see some form of critical failure sustem re-introduced, I like knowing there's always a chance I could kick myself and cripple my groin.
I agree with this. Weapons degrade in Fallout 3 to add immersion because it makes it more realistic. However, the items degrade unrealistically fast. First off, in FO4 they need to make items degrade more slowly. Next, you should be able to use your work bench/scrap metal to repair items. Lastly, there should be merchants that can repair items to 100%, for a high price of course.