I'm using mine still, with no issues. I'm planning on getting it swapped when the new ones for that are available.
The description of the problem from Samsung that I read said the issue is that the batteries that have failed have done so because the cathode made contact with the anode. Which of course is an obfuscatory way of saying the defective batteries have failed because they directly shorted out internally (for a reason not divulged). That says to me that shutting the device off and leaving it be probably reduces the chance of that occurring, but doesn't eliminate it. Charging and discharging make heat, and heating/cooling makes things expand and contract.
I do think it's playing a bit of Russian roulette to keep using my device, but like the previous person said, it seems like if your battery was going to short, the chances of it doing so have been greater while it was still new. I think the more charge/discharge cycles it survives, the less likely it is that it's one of the ones that will fail, or fail soon. If I end up with a big leg burn, I'm sure I will regret it no matter what
When I leave my phone charging at night, I leave it placed in a Pyrex baking dish. Unless it 'explodes' so violently that it goes airborne, I think that will keep things safe, even if it sets off the smoke detectors?