I should point out that RC4 is not adequately secure, I recommend using UDP exclusively and not use TCP

Datagram Transport Layer Security (DTLS) to encrypt UDP traffic. Still I am not sure this will solve the problem with torrent monitoring.

afaik RC4 was not intended for security, but to obscure traffic from ISPs. it's not effective for this purpose either in wake of Deep Packet Inspection.

You need to raise this issue at Bittorrent Enhancement Proposal level and find good arguments that haven't been voiced before.