manual trans yes
what you said about the putting the engine speed sensor on the motor is a good idea, but when stopped in traffic it wont be spinning at all so the ecu might think the engine is off.
first and second gear will never be used, so when going under 20kph the motor might not be spinning fast enough for it to register :O
will be using 3rd and 4th or maybe 3rd and 5th depending on motor rpms and how it feels to drive.