1. Regarding "no religion' being more likely to support assisted dying. That's just basic logic. Atheist's believe that when you die, you die. There's no inner turmoil about whether a mythical soul will end up in a place called Heaven or Hell when you die. It's not hard to work that out surely? If you live by the command of a mythical being, then you will be subject to the issues raised in following that mysticism related to whatever they say happens about death.
2. Regarding the "risk of coercion and elder abuse' - oh yes, it needs plenty of oversight, a very strong and complete set of guidelines and rules. But for someone who suffers immeasurable pain and suffering for decades, with no prospect of a cure or relief, are you really lacking compassion for that person, when they knowingly choose to end their suffering in their own dignified way? Or is it just thoughts and prayers for their time of suffering, and it will be fine when they naturally die, as it will be great in the afterlife?