I'd be interested to see where everyone's payload numbers came out. I don't have the math I did anymore, but it's clear most of these small vehicles aren't meant to tow much. A 5,000# tow limit sounds great, till you realize that with two people, a full tank of gas and a cooler of food, you're already at your payload limit.
I think if you have a good feel for vehicles, you can tell if you're overloaded. My old motorhome was dangerously overloaded, from the factory. With my truck, mostly I'm shortening its life towing a trailer whose size and weight Toyota didn't really intend, at least for common use. As to safety, I've towed up and over a lot of steep passes, through winds and through city traffic. I've had to slam the brakes
in town, and keep it under control in those high winds and steep downhills. It's always been under control.
But I think it's worth going through the exercise of adding up how much weight you'll realistically have in your vehicle, including passengers, when you'll be towing. If you know you're 500# over your payload limit, your driving style will likely be much more conservative.