It's apparently the same actor as Tarkin.

It's a terribly unpopular opinion, but I actually really like that their cell is localised to Lothal. We can explore the galaxy in every other piece of Star Wars media, I really want one show to just explore one planet, or system in a really in depth way. It's a pity Rebels does neither very well.

The Trayus academy was actually shown in the mid season trailer.

Actually this episode's title was changed from, 'The secret of prisoner X10' to 'Legacy.' That's not the next episode's title.