Hi John
Ive not looked at the main earth ,but i had recently changed the battery for something a little larger,so this maybe something self inflicted...(hopefully).
As for the fuel filter? the car cuts out, and will restart again at the turn of the key,but as the car has been stood for a year,this could definately doo with a look.
As for the scanner,is it a one off price with future chargeable costs when updates come online?