Magsafe-2 car charger for 2015 MacBook Pro

Yes they're compatible, however if the wattage of the charger is less than what the MacBook needs, it may not charge while the MacBook is running. That's typically only a consideration when you're using a charger from a smaller MacBook on a larger one. It shouldn't cause a burning smell or other malfunction.

If you're smelling burning, I'd get it checked out. Those things have been known to melt, particularly around the Magsafe connector, or where the cable meets the power brick. Check for frayed wires, etc. But I doubt it's related to using it on a different MacBook.

You might want to check your power adapter's plug as to whether the debris stems from there. If the plug is all right, I'd just remove the debris and not worry any more about it.