> The problem I see here is that if my LAN goes down for some reason, I might not have access to my passwords
Not entirely true, you will still have read-only access.
I had a similar concern when I thought about self-hosting password managers. So I started a discussion regarding the same here.
Learned a lot of new stuff from the folks discussing here, take a look once, might help answer some of your queries as well.
Maybe you're right, due to the rise of dns level filtering many companies try to host ads on legit domain. I know YouTube does this for sure. But since I've been using this setup (from past ~6 months) the amount of ads I have seen practically have dropped down a lot and even from the adguard stats I can see that almost 18% of queries are blocked so it's a win for me.