PETG is going to work a lot like PLA in the aspect of it's looks but you will need to bump up the extrusion temp by 30c and the bed should stay about the same at 55c or so. So your extrusion temp should be about 245c to start and depending on the manufacturer you will need to adjust a bit more.
Sorry to hear about your trouble, and sorry for the delay in response time. https://github.com/BCN3D/BCN3D-Cura-Windows/wiki/Updating-the-BCN3D-Electronics-firmwareThose are the instructions for the traditional method of updating; were you following those when "something went sideways?" What happened, specifically?