Helicomparator
You can only take off again ("legally", I mean) either if the appropriate maintenance actions for the chip light are carried out and signed off by a licensed engineer, or if the MEL allows you to depart with the unserviceability - which in this case I very much doubt.
Not necessarily. Here in the US a private pilot can pull a chip detector and determine it is just fuzz.
Even on an air carrier certificate, pilots can be trained and authorized to do it. All my pilots are trained ass such---all perfectly legal.