Costa Rican Spanish

I have been noticing that people here speak in exaggerations, be them diminutive or hyperbolic.

For example, here are some frequently used phrases:

¡Qué barbaridad! - That´s outrageous! (Literally, what barbarity!/what an atrocity!)
(My host mom, Cecilia, says this a lot, most notably after I told her that I had to take two crazy buses all the way across town last week)

Es muy feo. - It is very ugly.
(This is a very common phrase to use here, even for someone mundane things: for example, my host mom said 'Té sin azucár es muy feo. Por otro lado, té con demasiado azucár es feo también.' (Tea without sugar is ugly. On the other hand, tea with too much sugar is also ugly.))

Es un pecado. - It is a sin.
(Also used to describe seemingly mundane things, that are hardly a sin.)

Diminutive:
Diminutives are used frequently, especially by women.

-cafecito - little coffee (I don't think I have heard my host-mom say café ever. It's always cafecito)
-tecito - (little tea)
-un ratito - (un rato means a little bit, as in descansa un rato (rest for a little bit), un ratito means a really little bit)

Other words you probably won´t learn in the classroom:

-mota/grifa - weed (grifa is a more colloquial Costa Rican way to say it)
-Pura Vida - Can be used in greeting or parting. All Costa Ricans say it to each other. It is literally translated as 'pure life' but can mean 'This is living!'... It's basically the Costa Rican Hakuna Matata.
-rico - (literally rich, but can mean 'incredibly delicious' when describing food. But it can be used to describe almost anything.
-lindo (adj or adv) - lovely, nice, pretty/ beautifully, nicely, very well
-Artista - Cecilia and several of her friends told me I was 'muy artista' when I figured out how to ride those buses all over town. (Her friends said that they wouldn´t ever do that, and they know the city!) I think they were saying that I'm very crafty.
-Tranquila - Calm down. Usually used as a command.
-Comida típica - native-style, traditional food
-Buen Provecho - Bon appétit. Do we have a phrase for this in English? Or do we just have to borrow from other languages? I have heard several people try to translate it for me; one very adorable older guy told me "Have a good... appetite." And he told me that when I was sitting on some stairs, eating a plain slice of bread.

Once I can fluidly incorporate these phrases, I will be one step closer to blending in with the Costa Ricans... I think my blond hair makes me a very obvious extranjera, though.