If I were risk averse, I probably wouldn't be riding on roads getting passed by 70 mph texting drivers. Not saying I don't think about failures, just put it into context. I'm far more worried on a 35 mph descent with a modern CF or aluminum bike than on my 1973 super sport, lighter is not always better and when things get pressed to limits.

But as far as your question, the thing I have to have up to recent standards is brake pad materials. Some of the older stuff is fantastic also, but when I get a new bike I'm always suspect of dried out brake pads and also wheels (never sure what condition they were in at one time). Wheels always hit the truing stand for a very close inspection prior to any ride longer than a mile or so.