I still like the idea of capping the bandwidth of non-donators. This is in no way forcing people to pay for amvs. Rather, it is forcing people to pay for a faster download ability.
As for bittorrent, I was of course not referring to putting all of the videos on it, but only the most popular videos. It's unfortunate that every time you have used it, you got slow speeds, but you should not judge it on that. it is very possible to get extremely fast speeds over bittorrent, and I normally do. It's like saying "the internet is slow because my downloads are always slow" :p
Also, bittorrent is used for a multitude of legitimate sites, unlike most other p2p networks.
An alternative to BT though, is
Dijjer. I have never encountered a site that uses it, but it looks promising. It seems to incorporate the advantages of bittorrent with the ease of normal downloads. It would be extremely easy to implement on either the entire site, or just on certain videos. I don't believe it should cause any drawbacks as far as download speed or anything, because it still downloads from the org when other users arent available. The only thing I see about it that might not be good, is it might not be compatable with the link obfuscation stuff you use here on the org. I think it looks quite promising though. Perhaps you could do some test runs of it on just a few videos just to see how it works out.