Yes, my car does indeed have loads of extras, Enhanced stereo system with added power output power, DVD player and TV tuner with surround system, all seats heated, front seats are cooled, electric seat adjustment and memory function, also electric mirrors, also tied in to the memory system, automatic wipers, headlights, Xenon headlights which are also linked to the steering wheel angle, cornering fog / spotlights, heated windscreen, back window, washer jets, headlight washers and mirrors, auto dimming interior and door mirrors, cat vision interior lighting, footwell lighting, puddle lights, every door has door open red lights for traffic approaching from behind, electric radiator cooling fan and also A/C cooling fan, electrical steering and oodles of control units, all talking to each other. So yes, there are loads of extra draw on the battery.
I already have a scan tool that can loads of things with the car but not at that kind of level you're talking about, in fact I expect that a tool capable of such advanced functionality is going to be restricted to dealers anyway, or mega expensive and thus not really a viable proposition.
As to getting 8 years from a battery, this is something I have not managed to do, the old one did last 7 years, but if you google you find that can done with AGM batteries, also typical last 2 to 3 times longer than an EFB one.