Sorry, but being new to EB, I can't somehow find answers.

1) Some EB players are talking about educating children of their faction family in the capital. How exactly one does so? Does it mean the parents of those under 16 (18?) must be kept in the capital? And what are the benefits?

2) Though I got used to the brilliant goverment system in EB, ocasionally I still don't have a clue about reasons behind some things. I.e., as a Romani, I conquer Tarant and Rhegion in the southern Italy, install there an occupation gov, then gov type I, then build various buildings, but still don't have an option to build barracks giving me hastati, principes and triarii (only a building for local levies). When will I get one? Does it have some prequisities that have to be build before?