I think BlackVue sells (off the top of my head) some graphite things (sorry) that attach to the wires, both ends. For treatment of interference of DAB antennas when placed next to the dashcam wires, maybe that's an avenue worth exploring if you do have problems.
As for the install, the most challenging part I had was running the rear camera wire through the tailgate harness rubber, other than that, it's simply tucked into the weather seals pretty much. Really easy.
I noticed they do batteries but I didn't really see the point. The car already has a battery and the Power magic pro prevents it from discharging to a state where you couldn't start the car. A bigger main battery could also be fitted. For me, mainly I didn't want to add any weight, mine's a 3 door hybrid.
Good luck with your install.