wow thats hell of a details.........
u r getting low speeds because there are not many seeders/peers for that particular file..
try downloading other torrents,see if the total speed increases..
but considering u r downloading a single torrent @30-40 kBps with not many seeds ,it is good speed u r getting..(only if u consider the single file.)..see the quote below
I use Utorrent..the speed that i mentioned is not from a single torrent..its the combination of speeds of abt 4-5 torrents downloading at a time..
if u ask abt a single torrent,then the highest that i got was abt 75kBps in a movie torrent...
i will recomend using utorrent..it is the best out there according to me...
visit this page and u will get all the details u want abt utorrent...
this is a direct link...no browsing required...
Tutorial to Maximizing BitTorrent Speeds with uTorrent - Bootstrike.Com
as far as spliting bandwidth is concerned,u r wasting the remaining 100-120 kBps not downloading anything..else..as u r getting a top speed of 30-40 kBps in torrents anyhow..
so as long as torrent doesnt require more than 30-40kbps u can safely download otherstuff..including other torrents..