First off, obviously, I’d never recommend breaking your local laws. This information only applies if your local laws permit, and this is not legal advice.
In a lot of countries, DDL is completely legal. The actual illegal part of torrenting tends to be the upload and, therefore, distribution associated with it. Don’t take my word for it, though. Your laws may vary.
Realistically, though, if you’re doing DDL from fitgirl, her site supports HTTPS, which essentially means that your traffic is already encrypted. Your ISP can’t see what you’re downloading, just that you’re visiting that specific site and maybe some API endpoints depending on how the webserver is set up. Of course, in a manual, or even potentially automatic review, they would be able to assume that you were downloading something due to the large amount of bandwidth coming from the website, but they likely shouldn’t be able to actually prove it.
WireGuard is faster, so use that over OpenVPN.
If privacy is a big concern, you’re more than likely to want to use a country that is very privacy friendly as a host. I’m unsure if the Netherlands is particularly privacy friendly. Switzerland and Iceland are usually considered the best. Though, that should not really matter much in your use case.
Proton should be fine. If you really care about anonymity, though, make sure to use fake details for your account. They did recently give out a user’s information–albeit for a much more serious matter.
For talk about VPNs and Privacy, r/VPN, r/VPNs, and r/Privacy (no VPN discussion on that one) is a better subreddit to ask.