Nice write up OP, you sure did some research, although I've heard about these quantum computers and how powerful they are, but I didn't actually know they were powerful enough to easily break into encrypted algorithms.

Anyways, one way I believe a way to keep your BTC safe, and I was expecting it to be the first on your list is the use of Hardware or Cold storage wallets, because these wallets operate strictly offline, making it difficult or should I say impossible for hackers to infiltrate, even with the help of a quantum computer.