Two ECU questions



I'm not sure if it's the right forum to ask, but maybe you will have some sugestions.

Basically I have two questions about Hayabusa 2000 ECU.

1. How exactly does ECU determine if an ignition coil is faulty? What does it measure?

2. How exactly do RPM limiters work? I was thinking about shorting CKP sensor signal after certain RPMs are reached (a hidden switch to prevent cops from measuring exhaust decibels) and restoring it after RPMs drop - just flip the switch and say "sometimes it behaves like that, I don't know why". Is it safe for CKP, ECU and engine, or maybe it would be better to stop the engine with other, more normal method (but it will not recover immediately after RPM drop I guess)?