AFAIK, Ghost splices into the CAN. So I'd contact rhe manufacturer of the vehicle. Tracker shouldn't invalidate your warranty, depending on how the fitter goes about finding the supply voltage.
For insurance discounts, contact your insurer or do an online quotes, with/without.
I have heard of knackered wiring looms after Ghost installs (well, ok, one anyway) but that’s down to the installer. I’d definitely check with the manufacturer but I suspect they’ll all disapprove.