Since the present tense of the verb "to be" is omitted in Russian, это is used as an indicating placeholder. When used this way, it still translates as "is"/"are" into English. Otherwise это means "this" in the gender-neuter case. It's like
"Rice, this is love. Rice, this is life," but that's too literal for a proper translation:
Rice is love. Rice is life.
In Polish, yes. Negation changes all the noun cases of the objects, that would normally take the accusative case, to genitive case. Not in Russian. Objects take the accusative case in the negation of the verb, but a noun takes the genitive case in the negation of the noun. For example, "There is no rice that she likes." Нет никакого риса, который она любит. Even the word который that describes the rice goes back to the accusative case, not которого genitive which would imply a male personal or animate noun.
You could also say that before the meal has even been prepared. Someone might ask, "How do you feel about rice?" or , "Would you like to have rice(with that)?". You might then respond politely by saying, "Well I don't love rice." - That is just one context, in which you are politely stating you don't love rice, where it can mean you don't like it.
Do not expect the division along a spectrum (such as "to love... to like" and "любить...нравится") to be the same in different languages. A good example of this with English and Russian is the English two-word spectrum "and...but" compared with the Russian three-word spectrum "и...а...но" (sometimes "а" is best translated as "and" and sometimes as "but").
I really like Lera Boroditsky's work in the area of differences in thinking associated with differences in language. Her short (11-minute) lecture "How the Languages We Speak Shape the Ways We Think" (https://www.youtube.com/watch?v=VHulvUwgFWo) is a brief introduction. By the way, Russian is her native language.