Alright; I called in Subaru yesterday evening and asked about the warranty concern.
They said anything that is non-OEM from factory and is put into the car is a potential ticket to void the warranty. (Of course after hearing this got me intimidated...)
Now I know they would have to prove that the problem would be the dashcam itself that is causing the malfunction; but after opening up the under-dash panels and discovering the ECU and all its electrical components are lying
right beside the fusebox... I did not install it just to avoid the potential hassle I can already see the dealer fussing about.
Anyways, instead I went ahead and routed the wire up the windshield via auto-dim rearview mirror wire harness cover, up and across the headliner, down the A-pillar, and into the glove compartment to the 12V power port. I know I am now stuck with a Blackvue HD II without Parking/Event mode...but until Toyota/Subaru finish re-flashing their ECU softwares (due to idles & CEL problems), there won't be any extra wires hanging out of that fusebox anytime soon...