1st, a further explanation of the mode for ftp. You can read up on "newline" on wikipedia: https://en.wikipedia.org/wiki/Newline

Basically, windows, linux, and mac all have different ways to terminate a line in text files (in the actual file, the bits that are used to indicate a newline). Because of this, if you open a text file on a windows system, in a client that is not written to understand different newline formats (ie. notepad), that was written on a *nix system and transferred in binary mode, the line breaks will be all fucked up. So ftp automatically converts files for you.

This would not affect binary files like rars or jpgs.

2nd, there's another reason why your rars and jpgs are not at 100%. This is a side effect of the bittorrent protocol. The torrent file is basically a list of checksum of a bunch of chunks. These chunks are some multiple of 2 and I'll use 4mb as an example here. Because it would be very rare that your have files that fall cleanly on each 4mb boundary, a file that's been modified will mess up 1 or more chunks which may contain 1 or more files. For example, you have:

32kb jpg 50mb sample.mkv 1k nfo 100mb rar ... 50mb rar 2k sfv

We will assume this is same order as the files were created in (this is not always the case). You have 2 text files here. If nfo is messed up, the chunk containing your 1k nfo and some of the 50mb sample.mkv and some of 100mb rar totaling 4mb would be bad. So you will see a rar and sample.mkv at 99%. Similarly, the sfv will also make the last 50mb rar not be complete.

I assume you're using windows. The easiest way to do a quick check is to open a terminal and complete file sizes to the byte. If this is the result of transferring files in ascii mode via ftp, then the number of bytes of binary files will match and the ones for text files will differ by a number of bytes. This happens to be the same number of lines in that file.