In Spain at least, "arroz" doesn't just refer to a dish of the white stuff by itself. It can also be a kind of stew where the rice is cooked with vegetables, seafood, chorizo, and other cuts of meat. Though it might have started out as a means to deal with leftovers, "arroz," when done right, can be quite a feast and not a cheap date at all!
Growing up with Minute-Rice, it is easy for us gringos to forget that in other cultures, rice is a very big deal and the subject of endless conaisseurship and outright snobery, not only in the Spanish-speaking world, but in the Middle East ("arroz" comes from Arabic "ar-ruz") and South Asia (where those overpriced packets of basmati come from)--to say nothing of East Asia itself.
'Bueno' is an adjective, and is used to describe nouns.
'Bien' is an adverb, and is used to modify verbs.
The confusion most likely comes from English, where we often say "good" instead of "well". (For example, "I'm doing good.") Other languages don't generally blur the distinction the way we do, except possibly as slang.
Great question. "Esta" is for feminine words, "este" for masculine, and the rarer "esto" handles everything else. "Restaurante" is masculine.
It said it was 'great rice', not 'good rice.' They mean the same thing! Just one is more enthusiastic. I guess I'm not feeling very enthusiastic today. ;P