I don't see how wiring in the ceiling interferes with installing panel mounts or running a panel cable. The only situation where you could damage the ceiling wires, is drilling a big hole for thick cables of the roof junction box.
If you have to do parallel wiring, you should (and could) try and avoid such a box. Run a short MC4 gauge 8 through the fridge vent and install the J-box in a closet next to the fridge. Very likely, there is a dead space on top of your fridge as well, close to the front where it doesn't get in the way of hot air exhaust.