I'd lower your global connections to 150 and have 50 max per torrent and say 2 or 3 upload slots per torrent, that way it should stop it going ott.
As for the upstream, not a lot you can really do yourself tbh Might be worth while taking a trip to the VM newsgroups. The folks there will check your connection from their end and see that your levels are out and book you a tech call to sort it out. That should be free by the way as its not your fault the signal levels are wrong
