can an ESC kill motor

[suicideneil]

^^ That is nothing to do with the esc, if the motor over heats the esc has no way of detecting it as there are no sensors like in the novaks. You have to manually check the temp of your motor during a run to make sure it isnt overheating, and adjust the gearing/voltage/programming as required.

On the Plett front, I's ask the specific setup when it died each time- sounds like the motor was just pulling too much current (its a 2600kv motor after all....) and cooked itself.