Do I need to press the tofu before step one in this recipe? Also, can I skip the shrimp paste?

As a salty fermented fish product, Shrimp Paste can be subbed by Fish Sauce. Omitting it in the presence of shrimp doesn't really make sense to me. It's like omitting soy sauce because a dish uses soy beans.

I'd also press the tofu. Mostly because I always press tofu. Best to do it when it dries after the boiling water bath.

I'd probably press the tofu, but the recipe clearly does not call for pressing. And I'd use the shrimp paste, but you'll get a good dish without it--note that the recipe writer snafu06 says to omit it if you use shrimp. There's a lot going on in the recipe, and you'll have a good result even if you can't follow it to the letter.