I have only seen "querer" as "love" to express deep emotional connections hetween humans. I can't remember if I've even seen it used for pets, for example. It is just not the same kind of love one has for soup that one has for one's mother, brother, or significant other. Or dog, if it's used that way. Probanly you do not gaze romantically at your soup and tel it, "I love you, baby." Probably.
I think it is because 'del' is definite (like "the one and only tomato in the world") and 'de' is indefinite ("a random tomato").
For exemple, you would say : "El sombrero de vaquero" if you wanted to say "A cowboy hat" and "El sombrero del vaquero" if you wanted to say "THE cowboy'S hat".
Hope what I'm saying is actually right and that it helps you :)
In Spanish, adjectives tend to come after the noun they modify. This is similar to the way Spanish has no "apostrophe s" for possesives. It would appear to be literally translated "soup of tomato", but the because the sentence is structured differently in English, it is more accurate to say "tomato soup". Basically, the adjective comes after the noun just because.