A few questions

[kemozz]

Why can I build barracks in some homeland provinces, but not in others? Am I missing something?

it depends on the military reforms. once you get to polybian reforms you'll be able to build barracks in all homeland provinces.

How do barracks work in type II government cities?

untill you reach the marian reforms you will only be able to build regional barracks.

How long does unrest last in type I government cities?

can't say for sure but keep building those 5% public order buildings.

Why do I only receive 600 a turn from mines when it clearly says 600?

i guess you mean 2000. the upkeep cost of armies is divided between the settlements thats probably why you're getting lower income. (not sure)

[MarcusAureliusAntoninus]

The Romans are unique and have restrictions on their MICs (barracks).

The mine thing is a RTW bug. It has been balanced so that the amount you actually get is where the EB team wants it. The amount it says is not accurate and was set the way it was (2000), so that you will actually get the amount that you should (600). The amount on the settlement details, income section is the amount you are actually making.