I think the easiest thing is to just use SOCKS5 in the proxy settings in uTorrent if your VPN supports it. I’ve used an AppleScript to check if my VPN is connected every 60 seconds and attempts to reconnect, but you could probably do the same to check if uTorrent is running and launch uTorrent if it isn’t and the vpn is connected. I’m not super adept at AppleScript Editor but some googling and effort would probably get you there.