Ḫattuša contained around 30,000 cuniform tablets, are all of them translated? What's the current statues on the other Hittite archives in Anatolia? Is there specific information we're missing on the Hittites that we expect/want to find on these tablets?

There's always more to be said on the topic, but I discussed Hittite archives in What are our sources for the history of the Hittite Empire? Only the most important historical texts from Ḫattuša have been translated into English, but virtually all of the tablets from the site have been published as line drawings in the KBo and KUB series, and many of them have been published in transliteration as well.

To look up a particular text, check out the online Catalog der Texte der Hethiter, which has line drawings, photographs, and bibliographical citations.

CTH = Catalogue des Textes Hittites --> refers to a text, not specific tablets (a text can be found on many different tablet fragments)
KUB = Keilschrifturkunden aus Boghazköi --> refers to a specific tablet
KBo = Keilschrifttexte aus Boghazköi --> also refers to a specific tablet