iknowwhatyoudownload.com is pretty unreliable. It lists some torrents downloaded from that IP and then likes to add some torrents (mostly porn in my experience). I've tested this with many connections over the years, and it's not just sharing/rotating IP addresses that triggers this.
(My use case for iknowwhatyoudownload.com is mostly to see what public torrents other people have in their seedboxes.)
Also, I wouldn't worry too much in Germany unless you're downloading the latest YTS release or something. There are a few horror stories out there about being sued, but they are mostly exaggerated and not recent. That said, your setup sounds very solid and you should still use a VPN.