I've just started the EI torrent to see what's going on.  The availability of a torrent is unrelated to the integrity of the files on Archive.org's server.  So if the torrent won't work for you, just go into "PDF" (above "torrent") and download the files individually. 

Back to the issue of the torrent.  The way BitTorrent works is that when you start downloading a file, you are fetching it piecemeal from the computers of everyone else who is also downloading the file.  It's not coming from Archive.org; all they're doing is maintaining the index of who is online with bittorrent at any one time, swapping the EI files.  Everyone is sharing from their individual computers. So, at the same time, you are performing the same service for everyone else.  That's why your computer says you are uploading something.  You are - the parts of the file you've just downloaded, that other people still require.  It's a decentralized, sharing system.  It's a Good Thing, and nothing to worry about.

In the present case, under "peers", I see (at the moment) two "seeds", both in the USA, that is people who are sharing the file with me.  Both show 100% progress, which means they both have the whole file I'm trying to fetch, all of EI.  As long as these two seeds stay connected, I can expect to to receive 100% of the file.  But sometimes none of the people connected has the whole thing, everyone just has parts.  That's when the transfer can get stuck at a percentage less than 100%.  Everyone then has to wait until someone comes online who has it all, and then everyone else can get the missing pieces.  Once a few people have 100%, and are online, then things are usually fine.   Imagine a big jigsaw puzzle, with people copying and sharing pieces.

While I've been writing this email, my two seeds have gone offline.  Now, there are no seeds, and under "files" I see that all my PDFs are stuck somewhere in the 80% range.  I just have to stay online, and hope that more seeds come online with the whole 100%. 

With something of specialist interest like EI, there may not be enough people worldwide to make bittorrent sharing successful.  If it's just a handful of people sharing, things can easily get stuck.  With something like a popular film or CD, there can be tens of thousands of people sharing, which means the whole process works smoothly.  (I am not condoning copyright breach.) 

Best,

Dominik