P1709 sounds interesting. The car doesnt know when its in neutral or park so would probably have something to do with it wanting to stall.

You can try getting the ECU reflashed which will just update its software. This is something you could hazard a go at but judging by the extent of the problems, it probably wont solve them.

Disconnect the battery for about an hour then reconnect. This will erase the ECU keep alive memory and go back to a default set of settings.