1) Drupal: I can't tell you much about that, only that i think there is a possibility to connect user accounts databases from third-party software. Please wait for further answers …
2) Spanish language: We are very sorry that we can't offer a spanish language pack to our users, we know how important this language is. Translations are a lot of work! Our translations have been done by private translators which were offering their services to us, not by professionals, but no spanish translator offered his services to us. We ourselves of course can't translate the board to other languages than German and English.
We do not seek for new translators with our actual language system any more. We would of course still appreciate completely finished additional translations for WBB 3.1, and would be glad to offer them to our customers. But no-one has offered an additional completely finished language set to us …
For the next version of WBB we are changing the translation process so that - as we hope - more translations will become available more quickly …