I would assume that most members don't use a VPN where it is not necessary (I personally don't use one). You're probably getting bottlenecked by the VPN, because of all the encryption and decryption you have to do on either side.
Chances are you don't need the VPN so I'd just drop it entirely, at least to test the waters with your ISP. If you get C&D letters, then you'll know for sure, but it sounds like you haven't taken things that far and are just playing it safe (read: paranoid).
Whether it is safe to seed here or not depends on the laws governing the country where you live.