

I’ve never used them but I heard about them in the context of private DNS and VPS hosting. E.g. they act as a middleman to shield domain the shield the client from authorities (at least to some extent — they still have to follow the laws).
Given their focus on privacy I’d trust them for torrenting at least as much as the other options. As a first VPN I’d say it’s great because of their flat 5€/m price. A few years ago I used Mullvad for that purpose — until they removed port forwarding.
Yes, but the point is keeping the quality the same. If you reencode a 5000 kbps x264 Blu-ray encode to 3000kbps x265 you will have visibly worse quality.
If you encode the corresponding Blu-ray remux with x265 to 3000 kbps the result will likely be nearly indistinguishable from the 5000 kbps x264 encode.
For OP: I also prefer smaller releases so I download mostly h265 WEB-DLs. They are usually around 3000-5000 kbps (1.3-2.3GB/hour) and look fine (especially as they usually come with HDR).
Redownloading WEB-DLs in the right size will give you the best quality for the small size (and saves energy, depending on where you live).