Yes, internal coolant consumption can damage a catalytic converter.
yes it can
That depends on the engine and the fuel you've used. If the engine starts burning oil a catalytic converter can fail rapidly. Some fuel additives can also cause a catalytic converter to fail prematurely.
Having no catalytic converter installed is illegal and can cause a myriad of problems. Probably not a backfire though.
No, the catalytic converter is downstream from the EGR valve so it has no effect on it.
Yes
No, the catalytic converter has nothing whatsoever to do with your defrost system.
A bad catalytic converter can cause hard starts if it has become clogged. This produces excessive back pressure in the engine.
The smell of rotten egg is coming from your catalytic converter that is plugged up White smoke is an indication of water (usually antifreeze) in the exhaust.
A bad coil can damage a converter. If the engine is misfiring, it will cause raw fuel to get into the converter and that can cause failure.
No
Yes
it is ok to continue driving the vehicle while the catalytic converter is not working properly?