Damo,
The tech costs are enormous for the first part of the game, and the Ottoman Empire was well ahead in most fields into the 16th century.
Keep in mind that we have a 1337 start and the Turks don't start with their usual tech advantages (nor should they, in their infancy). Latin until 1568, it seems to me, is necessary. Orthodox at the very least.
As far as the Timurids, I forgot to add. Their events will be slept and they'll be bumped to Ortho as well. If they're played.
EDIT: Ah, and Austria is only having its usual cultures restored. Hive removed them, presumably, as a gesture to historicity and on the assumption (erroneous, as it turned out) that other countries would be limited to the same degree. If England has French, which it must have, and the Turks have Arabic, Austria with Magyar, Slavonic, Slovak and Czech is pretty reasonable.