I am currently trying to seed a large 300+ gig torrent of which I am only hosting 3gb worth of the files. I have all other files set to download priority "off" and they did not go at all until my 3gb download completed. Now when I am seeding those files the client decides to starting downloading little pieces of the files that say "off" which is screwing up my ratio. Is there a way to truly stop them? I can set the limit to 1kb but it seems really stupid that it feels the need to download files I told it not to just because it isn't using other resources.

In three years period of using Tixati I have never seen that the program downloads something when a torrent is in "Seeding" status. Check what pieces of other files are being downloaded. See if these are first or last pieces of a file. If so, it is normal and you can do nothing about it, all clients will do the same. Those pieces span two or more files, one of them is selected to download. If a torrent is particularly badly made, you can download a lot of unnecessary data. It depends on files sequence in a torrent and the piece size.