Power steering runs off of a pump directly attached to the serpentine belt. The second the serpentine belt is gone, power steering is gone.
The alternator loses power when the serpentine belt is gone. That leaves you on just the battery, so after a few minutes you’ll get a low warning on your battery because the alternator isn’t providing it power anymore, but you’re still drawing power from it.
The water pump and potentially fan (depending on the engine) are gonna go out with the serpentine belt, which means your engine and coolant will gradually climb up to overheating temps as the coolant is no longer getting cooled or cycled through the engine.
Yes, probably run an outdoor CAT6 cable and bury if needed.