That's strange, I like soy sauce (though I have not eaten it recently) + I am confident that many of the Bulgarian salami have a significant quantity of soy in them (though I try to pick better quality ones). I have not witnessed anything strange with me so far. Soy is also a traditional chinese product, I think. Maybe it depends on the soy quality and the extend this "soy" is real soy.

About soy milk... my god... there are so many cows that are waitng to be milked. Don't be cruel!

The real milk is the better choice, I think, unless you are allergic to milk. Personal opinion.