[Nyororin]

Kind of right, kind of not.

大好き is certainly not too strong to use for food or something like that.
It is perfectly reasonable to use it in the same situations as you would use "love" in English. Over using it sounds just as stupid as doing the same with "love" in English. There is nothing at all wrong with saying that you 大好き Japanese food. But if you use it in place of any "like", then you have a problem.

愛してる and 大好き exist so far apart in ranking that they are literally in different worlds. A good way to think of it would be 好き = like 大好き = love 愛してる = in love with

You can say you like pizza and you can say you love sushi, but if you say you`re in love with ramen... You`re going to get stares.

As for the second part, I`ll agree on not using 恋人, but boyfriend is almost always 彼氏 - not just 彼.

Maybe pronouncing the す with a strong accent, or emphasizing it wouldn`t be good... But there is nothing wrong with saying it. It really isn`t silent, particularly in polite speech.