Are aftermarket power cords required to be UL / CE approved?

Good question.  I would love to know as well. 

“Am I liable if someone gets shocked?” Maybe, but if it’s a defect in the cord, you point to the manufacturer. Same if it’s UL listed.

”could my homeowners policy deny a claim if they determine a non approved cord denied a fire?”  Unlikely, but every policy is different and the policy language would have to be reviewed. 

In the US are these cords required to be UL or CE approved?

No.

But look. Americans are such snowflakes they can’t ride a bicycle any more without a helmet. So of course everyone gets their panties in a bunch over electricity. A simple amp mod question a while back generated:

1. You’ll kill yourself
2. Even if you unplug it (!)
3. You’ll burn the neighborhood down.

Not kidding. Actual comments. The Greatest Generation we are not.

A picture of the actual amp mod in question can be seen here: https://systems.audiogon.com/systems/8367

Looks pretty scary, don't it?

This thread will now go on for pages and pages, getting worse hour by hour and day by day, until at last its the same three guys bantering endlessly back and forth. So much potential. So wasted. So sad.

millercarbon

So of course everyone gets their panties in a bunch over electricity.

You wear panties?

A simple amp mod question a while back generated:
1. You’ll kill yourself
2. Even if you unplug it (!)

Sorry, but you don't know what you're talking about. Components that are unplugged can still contain lethal voltages. That's especially true of amplifiers, but can also be true of things such as preamplifiers.