Hi pappy and welcome to the chordie forum!
Lots of songs have "chaff" that is unnecessary and that can be edited out. About the only thing that cannot be changed (as far as I can figure out) are the letters of the song's title and subtitle. Seems that if you alter the spelling, the index can no longer locate the song - capital and lower-case letters can be altered, but not the letters themselves.
Yes, the {sot} and {eot} codes mean start and end of text. Usually, these codes are merely artifacts from the source site where chordie found the song. Usually, you can delete these codes without any ill effect.
Likewise, you will often see many lines of stuff that start with '#' and these lines can also be zapped. Occasionally, these lines may contain useful information and by deleting the '#' you can make the line visible.
Also, many songs have extra blank lines that can be eliminated to help them print more concisely. I have run across songs that have more 'junk' than song . . . once you play around with the edit feature, it gets easier and easier to improve a song's layout and content.
Some users copy the 'raw' songs into a text editor and make their changes there so they can work offline. I prefer to do my editing in chordie so that I can hit the 'save' button and see how my changes affect the layout.
If you can reply and include a link to a particular song that is giving you trouble I can take a look and maybe give more specific advice. James