Yes, probably a good idea to do the programming with the inverter on the bench. Can be done in the vehicle as well but safer to do it on the bench.
Power up the inverter with 12V. The arduino is usually powered via the USB or serial programmer used. If you want to catch all messages comming from ...

Yes, one Arduino setup is what is needed and termination resistors in both ends of the CAN-bus.
I connected as per this: http://productions.8dromeda.net/c55-leaf-inverter-protocol.html


Hey bexander, I'm looking into doing the inverter swap and it seems like I will need to write the resolver ...