Loss of power, and a converter that gets red hot.
Yes it is possible.
They can become clogged or they can burn out.
Yes, you can do serious damage to the engine if the converter is clogged.
A bad catalytic converter can cause hard starts if it has become clogged. This produces excessive back pressure in the engine.
The common malfunction would probably clogged or resticted cat conv. Symptom would be no power, wont get up and go.
Yes, a clogged converter will rob you of power and speed.
No a bad muffler shouldn't, but a clogged catalytic converter will.
Yes, if it is clogged very badly.
A clogged converter will cause an extreme loss in power, poor mileage, and hard starting. If it is clogged really, really, bad it may cause the engine to not even start.
Most cars won't even run is the converter is clogged. Clogged converters can get very hot, maybe even start fires.
If it is glowing red it is partially clogged or the engine is running rich.
Hard starting, loss of power, poor fuel mileage are symptoms of a clogged converter.