After it was closed the question was edited by others to be a more-generic, depersonalized question about balancing those conflicting needs. If the question were newly-arrived in that state it would probably stay open -- though we might ask for a little more detail. But it was a major edit that the OP has not yet commented on, and it feels like the edit, while thoughtful and well-intentioned, removed too much of the motivation.
Thank you so much for taking the time to consider my question rather than rejecting it out of hand due to to the personal details. I appreciate Sarah's edit-- it boiled the question down, and I did feel it was a lovely gesture.
I've had more time to think of this from a moral perspective, and there seem to be several inquiries contained within the first one, for which I have received some helpful answers. Beyond the authority of an elder vs. halakha, I think there's a sanctity of life and the dignity of a spiritual being tied up in 'the system'. So, to break it down further:
How is "hospice" viewed in the context of Judaism? Without getting to personal, I have encountered a lot of people saying "its about comfort" while, in the same breath stating that by not providing activities, stimulation, etc, the person will lapse into a more vegetative state and/or get depressed, stop eating, and die. I'm having a lot of trouble with this because it seems like seeing someone bleeding to death of a cut and just stepping over them (or holding their hand, if you want to buy the comfort spiel) rather than trying to stem the flow. I'm very confused as to how any of that is "comforting" or "providing a meaningful end of life experience" (direct quote from this place).
How can I help my loved one retain their dignity and spiritual sense of self in the face of a system like this? I'm sure hospice workers are have good intentions, but this new place is very secular and they seem offended by the fact my loved one has different needs. I did find a very nice pamphlet at the old place called "A Jewish Response to Dementia" by Rabbi Cary Kozberg, in which he emphasized that its important to allow that person to participate in whatever way they are able. (My grandfather and I sang some songs today and he remembered the words, even if he couldn't remember what city or state we're in.)
How/Should one maintain a relationship with an elder family member if that person is abusive and/or bent on violating mitzvos?
How should one handle "unconscious" violations of the self-harm taboo? There are instances (actions during sleep, during a seizure, or when an autistic child "stims", for example) in which a person would not take those actions in their right mind, and stops as soon as they are aware of what they are doing.
And this last one may get too personal, but I worry about my culpability in this situation, even though I do not have the POA and the system seems to be against me.
Thank you so much for taking the time to consider the spirit behind my question, and not just the plethora of personal details.