How do I prevent LaTeX-Suite from opening files automatically when there's an error?

let g:Tex_GotoError=0

in your ~/.vimrc should do pretty much what you want.

According to the LaTeX-Suite documentation, pressing

\ll will take you to the location of the first warning/error.

Keeping this feature enabled may or may not be desirable for the situation covered in this post. On the one hand it is may be convenient to be taken to warnings/error. On the other hand, when the screen jumps to a new file, some info is lost. For example, when you return to the original file (using the methods below), it will look exactly as it was before it left, but the undo feature no longer works. I think the history needed by undo has been lost.

If want to keep the feature enabled and it jumps to a different file, then you can quickly return to the original file and location by pressing either

CTRL-^

or

CTRL-o CTRL-o

as mentioned in these posts: https://stackoverflow.com/questions/19971023/how-to-go-back-to-previous-opened-file-in-vim and https://stackoverflow.com/questions/133626/how-do-you-return-from-gf-in-vim.

If you want to disable jumping to the first warning/error, then see the answer by @JonathanProtzenko.