If the transfers already are slow using rclone, have you considered just mounting the directories you are using on the Hetzner to your local computer and just downloading the torrents directly to the mounted directories? It would stop using space on your local machine but you would still get to interface with the files like they were local. Also like you said the transfer speed is slow already so its shouldn’t be much of a hit on your speed or it might even make it better depending on how rclone is handling things. I’m not to familiar with rclone so I can say much about it.
I have used Linux for around 10 years. My daily driver has changed a couple times but I always go back to Mint. I think its better than Ubuntu personally. Its what I always recommend and I’ve been a sys admin for 5 years and dealt with production environments across all the core distros.
All that said it really depends on what programs you are using. Some have alternatives sure but sometimes that’s not enough. Sometimes you will have a program that just pins you to Windows until you don’t need it anymore.
You should list out what things you use that you need. Take some recommendations on their alternatives or how to set them up in Linux and see if it sounds like it’d work for you.
I can’t speak for the standard situation but for BG3 it isn’t “cracked” it ist does not contain DRM. AFAIK this is true for BG3 across all sources for purchasing. You should be fine to play with him.